Yabai T-shirts-ya-san are a 3-piece melodic hardcore and emo band from Oosaka. They were signed by Universal and Badass in 2016, and released their first full album with them.
- Koyama Takuya (こやま たくや, 小山拓也) – guitar, vocals – a film maker, producer of Sushi-kun. His middle school senpai Okazaki Taiiku (岡崎体育) also uses the Sushi-kun alias, and produces music videos for various bands in Oosaka.
- Shibata Aribobo (しばた ありぼぼ) – bass, vocals – big Michishige Sayumi fan.
- Morimorimoto (もりもりもと) – drums, chorus