(Um, Sorry) I’ve Been Reincarnated! - 126 – Stop It!

One of the top expert killers, tired of endless assassinations and having survived a cruel and suppressed life, decided to escape the world’s strictest assassin organization.

In all my life, I’ve only made two mistakes that I regret. The first was filling out my entrance exam application wrong, and the second was offending Zhong Yuan. If I had to use an idiom to describe the impact of my mistake, it would be simply, ‘Life is no better than death’. And if I had to use an idiom to describe Zhong Yuan’s offenses to me, it would be simply, ‘Too many crimes to record’. And yet, for as evil and wicked as he was, he attracted girls the way that flowers attracted bees and butterflies.

It happened that one day, for some reason, I taunted Zhong Yuan, “The King of Hell sent you to torture some more people, didn’t he?” Without a change in expression, he replied, “In order to torture fewer people, I decided to just choose one person to torture for the rest of my life.” I asked him, “What do you mean?” He smiled at me and answered, “If you don’t go to hell, who will?”

- Description from Novelupdates

The story is about a man whose compulsive tendencies make it impossible for him to keep a job, and a young girl who skips school and loves insects. The two meet, come to support each other in reintegrating into society, and fall in love. There’s a problem, however: namely, the parasites in their heads.