If you didn't know, the nickname comes from an extra chapter, volume 16 of the Haikyū manga.
The Oikawa hanger was an extra you get when you buy the Seijou jersey...
━━ HAIKYUU TRIVIA. a book of facts and random stuff about haikyuu!! ©︎ I do not own Haikyū! or the charact... Mais
If you didn't know, the nickname comes from an extra chapter, volume 16 of the Haikyū manga.
The Oikawa hanger was an extra you get when you buy the Seijou jersey...