The main character is a trap, whose sole purpose is to convert others into trap by whatever means possible. He seeks boys with feminine features or behaviors and through very comedy based tactics convinces them to embrace the trap life style.
Amahara-kun+ is a completed manga by Hinaki, first published in 2011. It blends romance, comedy, boys' love and slice of life. You can read all 8 available chapters of Amahara-kun+ online for free on MangaPulse; the newest is Chapter 7, added 2018-02-22. The series is finished, so you can read it from start to end in one go.