When his father remarries in his fifties, Haruki suddenly becomes step-brothers with Hikaru, a boy ten years his junior. Hikaru usually is a shy boy, but he likes Haruki immediately. Like an ideal little brother, Hikaru asks Haruki to play with him and spend time with him. But, Hikaru might like Haruki more than as a brother...and he might not be so innocent about it. (Source: Fantasista Inc.)

Kokoro wo Korosu Houhou was published digitally in English as How to Kill a Heart by Fantasista Inc. through futekiya from January 30, 2020 to June 25, 2020.