From Pixiv creator DC Ultra, whose works follow the story of university student Anna Blackthorn, who has taken on the burden of being her planet's hero, Ultra.

This is a confrontation between Anna and a perverted male teacher. Gallery contains parts 1, 2, and an IF bad ending (which starts on page 335)

Pixiv - https://www.pixiv.net/en/users/13098329

Vol 1: /g/2808388/797d828c62/
Vol 2: /g/2811481/5f0133ec90/
Vol 3: Here
Vol 4: /g/2816633/009864d77c/