Toumei Ningen no Tsukurikata

Toumei Ningen no Tsukurikata (透明人間の作り方, lit. "How to make an invisible man.") is a manga series by Eiji Masuda. It was serialized in Shounen Champion.

Plot
Shinji Saitou is a high-school student with a knack of playing pranks in order to cure his boredom. One day, following an altercation with his closest friends, he receives an e-mail teaching him "how to make an invisible person".

What follows is an encounter that threatens to tear him away from Sodegi Kana, a girl who reciprocates his feelings for her. It is this meeting with another girl, who shares a deep, yet unknown connection with Shinji, that beckons in his inevitable transformation into one of the "invisible people" himself.