Well, I was reading a study of Chinese fans about Bagua (“eight symbols”) from FranChouChou.

They found a correspondence between Kotaro and the number of the girls (assuming Kotaro is # 7) and their form of death and their character

They also predicted the possible cause of death of Tae and some other details of the death of other girls, and explained why Kotaro changed his name.

Bagua is an ancient Chinese philosophical study that began almost at the same time as Confucius and AnQi Sheng, just before Qin Shi Huang and XuFu, and then he was taken to Japan with Buddhism

The “Eight symbols” correspond to the death of the girls as follows:

​

 Tae: 0 (000), 坤 (Earth), death by earthquake or starvation​ [Prediction]

Sakura: 1 (001), 乾 (sky), traffic death​

Saki: 2 (010), 離 (Flame), death by gas explosion flame​

Ai: 3 (011), 震 (Thunder), death by thunder​

Junko: 4 (100), 艮 (Mountain), death by plane crash (if we refer to the accident of the royal saga at the time, it crashed in the mountain ranges)​

Yuugiri: 5 (101), 兌 (Lake), death by blades (兌 also corresponds to the “metal” in the Five Chinese elements) [Her neck all but confirms this, unless she died by hanging]​

Lily: 6 (110), 坎 (Water), death from heart failure​

Kotaro: 7 (111), 巽 (Wind), not yet dead  [Prediction]

​

Note that Kotaro used to have Inui “乾” as his last name, but then he changed it to Tatsumi “巽”, more about that later

There is also a philosophical implication for teaching the eight symbols:

(I translated the Chinese classic myself, it may not be quite accurate)

[edit by Virovac I changed the gendered pronouns put in by translator used] 

Tae: A person from 坤 (Earth) must remain moral and forgiving.​

Sakura: A person of 乾 (Heaven) must look forward and be optimistic.​

Saki: A person of 離 (Flame) should shine their light and personality on others.​

Ai: A person of 震 (Thunder) must be educated through [as in past?] fear

Junko: A person of 艮 (Mountain) must remain calm, peaceful and thoughtful.​

Yuugiri: A person from 兌 (Lake) must make and educate [their] friends.​

Lily: A person of 坎 (Water) must maintain [their] virtue and conduct. ​

Kotaro: A person of 巽 (Wind) must reiterate [their] orders and ensure the practice of [their] affairs.

​

Japanese Buddhism (which has many ties with Bagua and Taoism due to Chinese influence) classified the days into 6 groups: 大安 、 友 引 、 先 胜 、 先 负 、 赤 口 、 佛 灭 (I can’t translate these, are some ancient classical Chinese terms), and all the girls died in 佛 灭 (“仏 滅” in Japanese), the worst of the worst days according to the Japanese Buddhist calendar.​

You can see this on the website of Zls, where it says the date of death of each girl appears that they died a day of bad luck

​

Kotaro’s old last name “乾 (Heaven)” meant a lot of luck, but he changed his name to “巽 (Wind)” to make way for Sakura so she can take “乾”. Usually, [changing one’s name or symbol] is strictly prohibited and would bring extreme bad luck.

​

In that case, the eight people had extreme bad luck; However, in Bagua’s philosophy, going too far towards one end will take you to the other end, so the extreme lack of the eight really brings the group extreme good luck.

​

I just noticed that if the elixir of Xu Fu is given by AnQi Sheng, the “immortal” Taoist. for the understanding of the Taoists. They are not exactly “immortal” as in the Western understanding of “eternal” or “not aged” forever; instead, they would simply live an incredibly long life and eventually die of old age at some time (possibly inconceivably far in the future).

​

Qin Shi Huang wants to be immortal> sent Xu Fu to look for Anqi Sheng the Magician> He ended up in Saga and became a legend​

We only have small details about Anqi Sheng, which also means that it has a lot of mystery. Therefore, it is probably convenient to turn it into someone Kotaro found

Qin wanted XuFu to find Anqi Sheng and learn the secrets of immortality, and just as I said in an earlier theory it was Anqi who actually revived the girls​

As I said the legends of xu fu in saga, they indicate that it would still be located somewhere on the island of Kyushu, so it is quite likely that it is somewhere in Saga.