AFAIK and as strange as it sounds, it isn't a bootleg! Good Smile who made this is mainly a figure manufacturer but also dealt with anime and games. It does seem a bit fishy though...

Also considering Japanese copyright laws, they would have asked for permission and had good relations with the companies to do this. Had they hadn't, it would have been closed down by now. Many of the characters, the company did something (e.g. Hatsune Miku was their mascot when they sponsored one of the Japanese races, part of the production committee on One Punch Man).

The KOF bosses does scream collaboration event, common in mobile games. PuyoPuyo Quest had everything from KFC to the Sega connected stuff (Sonic, Persona, Detective Conan, Lupin the 3rd) with the same for Monster Strike but at least had sprites done in the style of the game. Maybe SNK weren't playing ball or didn't have enough time to do unique sprites?

Is this a bootleg? Why the hell are KoF sprites the freaking bosses in what's obviously a shonen-jump game?

Thanks for sprites! Waiting for Knights of Blood units and Chloe

It's probably possible to extract the scenery of the game, but I'm not sure if it is easy to extract or if they're worth it at all.

Is it possible to extract the stages/scenery of this game?

Can't wait for Miku Hatsune, Yu Yu Hakusho, Fairy Tail and Shaman King!

Well, this game is actually legit and is published by Good Smile Company, so of course these are all by them.

Jonluka is bringing Christmas early. :D Thanks to everyone who's been nabbing these together!

A bootleg game with unique quality sprites like these? The only re-used sprites are from KoF, but most likely for nostalgic reasons.

so this isn't a bootleg?

This game still has a lot of crossover sprites to be ripped in newer versions, including sprites of The Rising of the Shield Hero, Re:Zero, Fairy Tail and even a new Kill la Kill character that will be released tomorrow. A newer sprite extraction needs to be done.

"Thanks, Obama" was right there.

Bless you for these, Obama! \o/