Sunnyside Kindergarten Classmates

"In the far, far future…
""Jin"" opens his eyes with no recollection of where or who he is. All he knows is that he's bloody, bruised, and a damn strong fighter. And just like that, Jin grows up without it occurring to him that his past is important at all. That is, until he's captured by a security company named ""Scanner"" and meets strange men who claim to be his former ""Sunnyside Daycare"" classmates. It looks like Jin's going to have to strap in for a bizarre and horrifying adventure…"