The Missing "O" (Comic) Vol. 3 by Face Park

All the clues Mr. O left behind lead to Hong Minhee. Tall and handsome? Check! Purveyor of bad puns? Check! Mysterious thigh tattoo? Check! Heck, Minhee even remembers the night he rescued Eunsung seven years ago. Surely, Minhee is the elusive Mr. O. The long search is over! So why isn't Eunsung happy?
Binding: Paperback / softback