Non Refundable Alpha summary:

An omega named Choi Jaewon enjoys a carefree life abroad with his Alpha friends. When he returns to Korea after being deceived by his father to get some money, a marriage with his childhood friend awaits him - the Alpha, Yang Junhee! Unlike their childhood days, seeing Junhee now, Jaewon feels that he is Jaewon's ideal type, so Jaewon proceeds with the marriage. Jaewon promises something to Junhee, but Jaewon can't remember it at all. A sexual romantic comedy about Jaewon and Junhee soon begins!