Love/Knot (Yaoi)

Keigo Someha, a private detective and assassin, finds himself nursing Emiya Nozaki ― who had an unbelievable, near-death experience right in front of his house ― back to health. Emiya knows virtually nothing about sex and everyday life, thus Keigo feels that it is essential to shield him from the world's perversions. Meanwhile, Hamuro becomes fixated when he discovers Emiya's unique power, and he cunningly lures Emiya into a research institute!