Also known as: 間宮皆守
Hasaki Mamiya's older brother and the true protagonist of Subarashiki Hibi.
His appearance is similar to Takuji Mamiya, but with dark Blue Eyes.
Takuji, Yuki Minakami, and Tomosane Yuuki are his split personalities. He created Takuji and Yuki based on his deceased brother and crush respectively, while Tomosane Yuuki is loosely inspired on the real Tomosane and his struggle to reclaim his lost identity.