|“||A heart? ...I threw that away a long time ago. At least, that's what I swore. But if I can't even let go of my hatred, I guess I'm still human. Then maybe I deserve to be a laughingstock. Part of a cheap magic freakshow.||”|
–Seiichi Kugi, Extra Volume: 5656! - Knights' Strange Night
Seiichi Kugi (狗木誠一 Kugi Seīchi) lived on Sado Island until August 18, 2014, when he and his girlfriend Kanae Orisaki snuck onto the bridge connected Sadogashima and Niigata in their final year of middle school.
After Kanae's death, Seiichi joins the Chinese Mafia in the Western District and becomes an executive under Yili Ei, with whom he pretends to be in a relationship. Following certain events in 2019 (during which time he murders the executives of the Northern and Southern Districts alongside other persons) he escapes the island and seeks penance on Sado.
Seiichi returns to the Artificial Island over half a year later, where he tricks Hayato Inui into shooting him in the chest in the hopes that he'll die. He does not, and after he recovers he winds up back into the employ of Yili. Seiichi devotes himself to protecting her from then on out.
Seiichi has straight black hair, and normally wears a brown trenchcoat over a formal business suit.
As a child, Seiichi was described as "meek and quiet", usually just going along with whatever scheme Kanae had thought up. Still, he had a very strong protective instinct towards her. Though he was less adventurous than her (it was usually her that took the initiative) Seiichi enjoyed his role of being her protector and 'hero.' Her death triggered a swift personality change within him, and led him to reject reality.
As a Western District executive, he used to pose as a serious and determined individual, focusing on "making the island better". The people thought him respectable, and the Western District's Volunteer Police Force captain Sōji Kuzuhara also never felt like Seiichi was using him (at least, not until 2019). Seiichi seemed open and honest about his past, even steering into over-sharing territory with Kuzuhara at some points, but never obnoxiously so.
All this, however, was mostly an act. He was actually focused on getting revenge on the people whom he blamed for Kanae's death. In the climax of the first book, his obsession with revenge is revealed to an extent- but he is still focused on making the island better, believing that he is the only person capable of such a feat. He was willing to destroy anyone getting in his way and became more and more single-minded in his mission, which eventually caused his confrontation with Hayato. His facade falls apart completely, and his more unstable, obsessive traits become even more apparent. This was also the first time his death-seeking quality publically emerged; completely focused on killing Hayato, he wouldn't have minded getting killed by him (and after the battle, actually attempted suicide).
His hatred for Hayato comes from self-loathing from their similar pasts and coping mechanisms as they both escape reality in their own ways. Apart from that, he genuinely respects Kuzuhara - he seems to view the captain as a role model to emulate, someone who is legitimately a good influence on the island - something that Seiichi could only pretend to be.
After Seiichi returns to the island, and eventually finding a new purpose in protecting Yili, he develops a more stoic, focused personality. He detaches from most people...although Hayato can still rile him up, but even that eventually becomes almost a habit instead of genuine hatred. By the end of the short story collection, Seiichi seems more comfortable with his life, devoting himself to becoming Yili's shadow.
Seiichi has no hesitation over taking lives, (apart from Kanae's). He is ruthless, and has hinted that he has no qualms with torturing. He wears masks for most of the story - first the mask of someone who wants to change the island, and later a stoic mask, with only a few people being able to look through it: Kelly can see his more dangerous side, and Hayato can see right through him, which obviously annoys Seiichi.
He is also fairly dramatic - prone to thinking about himself and the people around him in a very dramatic way. At first, it is almost like a childhood adventure - detaching himself from reality, painting himself to be someone who can make the island better.... He gets over that delusion over the course of the novels - he continues to be dramatic, but in a more self-deprecating way. He has talked about giving up his heart to become the way he is now.
(Sections: Chronology | Trivia etc. forthcoming)
- Like Hayato, Seiichi's name contains a character that means 'dog.' He's known in some circles as the "witch's dog" and the "loyal hound."