Oretachi, Kore Kara

A story about the evolving relationship between two men who became lovers on a whim.

This story involves both partners switching roles and being penetrated.

Volume 1:
Sakuma and Ritsu have been living together for six years, but when one of them realizes the other one might be moving out, their relationship changes.

Volume 2:
A story set in the past, when Sakuma and Ritsu were high school and college students.

Volume 3:
Sakuma and Ritsu have been sharing a place for some time now, but after one of Sakuma's friends comes over, their relationship takes a step further.

Volume 4:
Sakuma and Ritsu continue their relationship as a temporary arrangement. After Ritsu goes out for drinks with a junior colleague from work, he returns home to find...

The chronological order of volumes is 2, then 3, then 4, then 1.

Official: DLsite

Official English Translations:
DLsite (vol. 1 & 3-4)
Coolmic (vol. 1)
MangaPlaza (vol. 1-2)
Renta! (vol. 1-2)

Official Chinese Translations:
Simplified: DLsite (vol. 1)
Traditional: DLsite (vol. 1-2)

Official Korean Translations:
DLsite (vol. 1-4)

Note regarding DLsite: a VPN may be required to view/purchase volume 2.