Himitsu no Kakurenbo Ecchi ~Spats Shoujo to Kakurenbochuu ni Noumitsu Seikou!? Boku to Naisho de Sex Shiyo?~

Natsuki is bored of the same ol' hide and seek with girls.
She'd rather mingle with the boys and calls herself the boyish pronoun "boku".
Until now it's been a platonic interest, but lately...

"Hey do you like, wanna... hide your thingie with me?"

A tomboy loli in spats spices up the game with s-e-c-r-e-t e-c-c-h-i.

[From DLsite English]