It’s a fun day at the beach in this Kill la Kill (キルラキル) illustration by animator Syūichi Iseki (井関修一), featured in the TakePro (竹プロ) collection from Comiket 86. Like the episodes, each of these illustrations also features a song title as the theme.
And if you’re interested in having an 80’s flashback, the song is Wangan Taiyōzoku (湾岸太陽族) by Oginome Yoko (荻野目洋子).