Touhou Koukishin ~ Adventures of Scarlet Curiosity is a 3D RPG released on 16 August during Comiket 86. An updated and remastered version of the game for PlayStation 4, as part of Play, Doujin!, was announced on December 28, 2015. The game was confirmed for localization on June 2, 2016, under XSeed Games, for the digital North American release under the shortened title of "Touhou: Scarlet Curiosity". In May 22, 2018, a Steam version was announced in XSEED's 2018 3rd Party Lineup Announcement Teaser Trailer.

Adventures of Scarlet Curiosity is the first Touhou Project game to be shown in E3.

Infamous vampire Remilia Scarlet has grown weary of her posh, centuries-long life spent with dutiful maid Sakuya Izayoi at her side. So bored, in fact, that when the local newspaper runs a story about a massive monster spotted nearby, she decides she wants a piece of that action! Unfortunately, she returns home from her first foray to find her mansion heavily damaged, with no clues as to who the culprit might be. But this only serves to fan the flames of the vampiric maiden’s interest in what’s going on beyond the walls of her estate, leading her on a grand, chaotic quest for answers…and for revenge.