An unofficial patch for Summer in Heat (夏のサカり) by miconisomi. It fully translates and uncensors the game, and includes other useful mods.

HF Patch does not contain the game, only mods. You have to buy the game separately.

Buy the game:
https://www.dlsite.com/maniax/work/=/product_id/RJ365188.html
https://miconisomi.xii.jp/summer/

HF Patch readme and releases:
https://github.com/ManlyMarco/SiH-HF_Patch#readme