My thoughts on dating... Dazai!
Credits to @kisara-16 because she basically co-wrote this through our conversations about Dazai. Seriously, these headcanons wouldn't look like this without her amazing insight on Dazai!
-Instant love is not an option when it comes to Dazai. He can think you're pretty when he first lays his eyes on you, and he can be impressed and admire certain qualities, but he's not going to fall in love that easily. Falling in love requires vulnerability and indirectly the acceptance of a possible loss. No, a slow burn sounds more right.
-Building up trust is the key to getting Dazai vulnerable. You're going to have to prove that you won't leave him. It's not an easy task as Dazai will make you face many challenges, like calling you up in the middle of the night because he's "too drunk" to walk home from the bar yet you're chasing him around the entire city up till dawn.
-However, there are more things needed to win over Dazai's heart. Little things over a long span of time, to be more precise. Dazai is a stranger yet attracted to sincerity and kindness, so a combination of these two things would pull his heartstrings.
-Imagine Dazai sitting at his desk and suddenly you put a can of crab on it. He's confused, but then you explain how you rarely see him eat at the ADA. When Dazai asks you why you chose a can of crab, you answer that he once tried to convince Kunikida to buy it for him with the promise he'd finish that long overdue paperwork. Dazai would be so surprised if someone, you, paid attention to him and remembered a detail from an interaction that didn't even involve you. (Credits to Kisara for this scenario!)
-Dazai would be oblivious to his crush on you at first, may it be because he's scared or the foreignness of the emotion. When Dazai does realize he has feelings for you, he tries to distance himself. As Dazai said, everything he wants is lost the minute he obtains it. He can't afford to add another wound to an already scarred heart. It's crucial to be consistent and prove you're not willing to leave, and that you desire to live.
-You'll have to confess first. Although Dazai easily picks up on other people's emotions and knows how to manipulate them, he has trouble handling his own. Vulnerability is something Dazai fears and that includes opening up about his feelings to you. He would wait until you make the first move.
-If you're scared though, don't worry! Dazai picked up on your crush on him as well as your struggle to confess. He'll tease you until you're convinced he needs to have some interest in you. Imagine being in the ADA kitchen and Dazai pops up behind you. His front is pressed against your back while he's trying to grab something that so accidentally happens to be at your coffee maker. "Don't mind me," he whispers softly into your ear. He could grab it much faster but why wouldn't he take his sweet time? After all, it's so cute how your body reacts to his close presence. And who knows, maybe it makes you confess sooner.
-When you do confess, Dazai might act light-heartened about it. "Oh, Belladonna, I knew you'd fall for my charms eventually! What about a lovely double suicide for our first date?" But don't let it fool you. He's excited yet nervous that you asked him out. He just needs to hide it for the both of you.
-You might also need to kiss him first. Dazai will turn it into a challenge to see how long you can resist kissing him. Imagine Dazai catching you looking at his lips. You turn your head the second you notice Dazai caught onto you, but then his slender fingers grab your chin, turning your head back to him. His eyes lock with yours, the air is filled with want... and then he lets go, focusing on whatever you were doing. The longer you wait for him to kiss you, the more seriously Dazai takes the challenge.
-Dazai's kisses are usually playful and teasing. He knows what makes you stand on the tip of your toes for more. One of the cuter things is when he taps on your shoulder only to appear on the opposite side to kiss your cheek.
-The PDA will be very clownery. Not sure if I wrote something similar for another post, but: If Dazai wants to cuddle with you at the ADA, he's going to drag you to the couch whining like a child needy for attention. It's all to hide that he craves your touch. Physical touch is an intimate action for Dazai as he rarely lets someone that close into his personal space and when he touches someone, it's rarely to show affection. Such an intimate action is something Dazai prefers to hide from his co-workers and strangers, so the way he goes around it is by using his desire for your touch to strengthen his reputation as a lazy clown.
-Nevertheless, there are going to be intimate, hidden touches throughout the day. He'll lightly bump into you at the copy machine. He'll then place his hands on your shoulders as if to steady you and innocently smiles "Sorry, can't have you falling for me again, sugar cube!" Or when nobody is watching and he delicately caresses your lower back for a split second. And perhaps the times your shoulders brush slightly aren't as accidental as they appear to be.
-Physical touch is more intimate when you're in one of your dorms, though. It's where Dazai doesn't have to worry about appearing soft or vulnerable. He loves it when you play with his hair, although it'd be an unfamiliar sensation at first. He'd relax so much if you made him lay his head in your lap while you do your skin-care routine on him. When you fill him in on everything that's going on in your mind while touching his skin aka giving him personal attention... He could never get tired of it.
-Dazai's favorite love language to receive is physical touch. He's so touch-starved, especially with the layers of bandages decorating his skin. It's going to take a long time before Dazai feels at ease and safe enough to remove the bandages around you, though. It's not something he's going to be comfortable with doing at the start of your relationship. Honestly, a lot of things that require even a bit of vulnerability turn into slow burns with Dazai. Even holding hands is a huge milestone that feels intimate to him. You really need to have patience and while you sometimes have to push him outside of his comfort zone or take the initiative, you cannot be too pushy either.
-Once Dazai agrees to remove his bandages, be extra tender with him. Kiss him softly and gently remove the bandages around his neck. Instead of staring at his skin and making him feel self-conscious, start placing kisses on his neck and then slowly trail down to the exposed part of his neck, leaving hickeys at places you couldn't before. Don't immediately let Dazai remove all his bandages. Take it step by step. Leave days between them. You don't have to remove his shield in one go.
-Dazai doesn't often initiate dates as he's rather easy in that aspect. It's not to say that he never takes you out, though! What Dazai values most on dates is the proximity of you and the memories that are being made. When Dazai wants to go on a date, they're rather spontaneous and unpredictable. One minute you're working and before you know it, he makes you chase him to a park. A fun date idea could be escape rooms! Of course, Dazai is smart enough to escape within five minutes, but he enjoys the proximity of it. He'll have already figured out where the key is, but why would he say it? Not only does that make you leave the room sooner, but he finds your cute dedication to escape it endearing. Dazai would also really like cafe or bar dates, but he also wouldn't say no to a date filled with surprises (if you manage to be sneaky enough to surprise him, that is).
-Dazai takes care of you from the shadows. He's a tsundere. So when he does an act of service, it's hard to tell it's him. For example, let's say you're very tired. When Atsushi is ready to grab a cup of coffee from the cafe, Dazai randomly brings up how tired you've looked all day. Next thing you know, Atsushi brings you a cup of coffee.
-Dazai isn't the one to get jealous easily, but oh does he taste it when somebody else thinks they can wrap you around their fingers when you're already wrapped around his. Softly said, it's not appreciated. It's hard to tell when Dazai is jealous, but he does get extra clingy and starts making it obvious that you belong to him. They're looking at your hair? Oops, Dazai is brushing it behind your ear. They're looking at your cheek? Dazai kisses it. They're trying to make a conversation with you? Dazai is answering all the questions in the most annoying way. They try to stand closer to you? Dazai has an arm around your waist, pressing you against him.
-When you need a hug for comfort, Dazai will make a remark on how clingy you are. But when you want to pull away, he hugs you even tighter and doesn't let go until he feels your heart rate go back to its usual tempo.
-Dazai prefers to sleep next to you. It doesn't necessarily helps him fall asleep (although it does make him feel more relaxed) but Dazai enjoys to have you in his arms, listening to your steady heartbeat and breathing, feel your warmth, and loves to have you close even though you're sleeping. It makes the night a bit more bearable and less lonely.
-Dazai isn't very used to praise, and if he does, then it usually doesn't mean anything to him. He knows he's smart. He's aware people perceive him as handsome. Nothing new. However, he'd secretly get flustered when it's you who praises him. It's the way you praise him with such sincerity and admiration without expecting anything back that makes the blood want to rush to his cheeks. Dazai knows how to smoothly hide his face, although you can still catch a tiny hint of him being flustered if the praise comes so unexpectedly.
-He's not always going to believe your praise, sadly. Not because Dazai doesn't trust you, but because Dazai doesn't believe himself to be a good human. So, whenever you praise him for being kind or beautiful, he's hesitant to internally accept it.
-Dazai calls you cringy pet names in public + Belladonna, but in the safety of your dorms he calls you "love" and "dear." All credits to Kisara and I'm still fangirling over how accurate this feels: "Sweet angel princess Belladonna, would you possibly... reconsider my double suicide offer?"
-Self-care does not come natural to Dazai. He is a pro in neglecting himself, so it is important that you motivate him in taking care of himself. Dazai will whine about how he does not want to shower only for him to do a full 180 turn when you offer to shower together. He clings to his can of crab, claiming it is all he need, only to change his mind once you make a delicious homemade meal (emphasis on you because there is something about knowing you made it that makes the food more enticing).
-To be fair, there are downsides to dating Dazai that you have to deal with. His acts of service often isn't noticeable, he has trouble opening up and sharing what is happening inside his head, and he requires patience on many surfaces. There are times he is as ungraspable as the wind. However;
-If there's one thing Dazai considers most important then it's your life. He has lost too many and he's not ready to lose you, too. So, it's almost a given that Dazai feels protective of you. He wouldn't let anyone harm you and if someone does... Well, that automatically makes them Dazai's enemy and we know what saying goes around. If you actually once get seriously hurt on a mission, it's going to keep Dazai up for the next couple of nights. Sure, the Agency has Yosano and she fixed you up like a pro, but still. What would've happened if they got you to Yosano too late? Especially if you got hurt in Dazai's plan, he'd beat himself up. Either way, he's going to feel like he should have predicted it. He praises himself for his intelligence but couldn't even use it to keep his love safe? Pathetic. Dazai is going to find it endearing though if you decide to stay up with him even though you're basically falling asleep on his shoulder.