Adult PC Game: Caribdis, VitaYok - FatesCrossed Ver.0.2.6 Win/Android/Mac/Lite Archive

"After a strange event that happened a few years ago, the main caracter lost his mother, and would probably still be living on the streets if it wasn't for the help of a mysterious girl named Lilly. She and her best friend took you in, in exchange for mutual assistance since she lost her body and you're the only one who can see her!"
"The search for your mother led to nothing but more disappointment. And so it would have continued until you received a letter that spurred you into action!"
"Now, you have to attend school while figuring out what really happened back then."