Ikisugi! Do-S Kyoudai ni Kakoma Rete

By chance, Hitomi gets a chance to be with her teacher Fujimiya, whom she likes very much. But the teacher's personality suddenly changes...! She is so embarrassed by the things he's making her do... Even the teacher's brothers joins in, as they awaken Hitomi's masochistic fetish...!

(Source: Fairbell, translated)

Note: Chapter count includes one bonus chapter.