Tengoku mo Jigoku mo by NISHIDA Higashi [Eng]

Manga Summary: 1-2.) Tengoku mo Jigoku mo (All of Heaven and Hell)
Himeno and Shirota have been friends since high school, even though their lives have gone in very different directions. They see each other occasionally, but both are wary of revealing secrets about themselves, so their conversations remain superficial. Until a pleading phone call at a crucial moment shows they both know more about each other than suspected.