Gomu+o+tsukete+to+iimashita+yo+ne+01+web+upd =link= Today

This designates the very first installment of the series as it was released on digital platforms (like Comic Seymour, RentA!, or MechaComic) before being compiled into tankobon (volumes).

: During the encounter, clear boundaries are set—specifically regarding safety, placement, and remaining external to her underwear. The protagonist violates these verbal boundaries, leading directly to the phrase that defines the series title. gomu+o+tsukete+to+iimashita+yo+ne+01+web+upd