D.Gray-man
Ongoing | hoshino katsura | 2004 released
253 i believe, if i got this right: Nea and mana were both the earl originally. then Mana ate Nea. and became the earl himself. then made himself forget he ate Nea. according to this chapter, Mana forgot once more that he was the Earl and went looking for Nea, forgetting he devoured him. At some point, Nea got free or something, and ended up inside of allen. (i'm guessing this part. they haven't said it yet.) now he calls the dog Allen, so maybe he gifted him the name or something after the dog died. Mana (millennium earl) is with allen for a time. while he was a child. and cross is also involved and knows these insider things. (as of yet, this is all i can figure out)
Me and my gangster neighbour