Four Elements Trainer, a free dating sim developed by MITY Games. Available for PC Windows and Mac operating systems. No voice acting.
Four Elements Trainer is an Avatar: The Last Airbender fan game in the hentai dating sim genre. You must travel the lands and train to bend all four natural elements, and the girls that teach you.
Source: N4G PC [NSFW] Hentai Game Review: Four Elements Trainer – Hentai Reviews