STORY IDEAS
HP x HQ! - Harry Potter would be a really good receiver (libero) in volleyball.
HP x OP - If Harry ate the deer-deer fruit, the mink tribe takes her in and that is how she meets chopper!
HP x HQ! - Harry could have gone to middle school with Hinata, and joined the volleyball ball club with him, and played as the libero. (Like maybe he chose that school cause it was reasonably close to his house. Like maybe his new home with Sirius is smack dab between Karasuno and Hinata's junior high, Yukigaoka. Like doesn't Hinata cross a mountain each day on his bike? Harry could live on that mountain.)
HPxOP - Harry (male or female) is reincarnated as the child of Silvers Rayleigh and Shakky.
Baseball player!Harry; like with the fast reflexes when catching and according to Oliver Wood (at least in the 1st movie), Harry had a strong swing, also from running away from Dudley and his gang he would have the speed!
Harry would call Sirius godfather, and be all formal with him when he/she is upset/mad/embarrassed with him
godfather - daifu
godfather - goddofa-za-
godfather - kyoufu
HP x OP
Fem!Harry
Sword Smith/weapon-smith!Harry
Harry x Mihawk
HP x TW
Hellhound!Harry
Fem!Harry (?)
Parish x Harry (?)
School teacher!Harry (kindergarten? Or Latin?)
Like Parrish she was drawn to Beacons Hill through the Nemeton
HP x Danny Phantom
MoD!Harry
Somehow ends up residing in the Ghost Zone
Fem!Harry (?)
Harry is technically the 'highest' ruling body in the Ghost Zone.
When in the Ghost Zone, normally stays with Clockwork.
Kuroko no Basket x HP
Fem!Harry x Kiyoshi Teppei
Harry becomes Seirin's manager. Same year as Kuroko, so 15-16 years old.