You, Forgive Me... Embraced By My Husband's Childhood Friend Nanami Tanaka

...A love across class lines. Koichi, the only son of a locally famous wealthy family, and Emi, who had only one parent, were at a loss because their marriage was strongly opposed. Takuma, Koichi's childhood friend, couldn't stand by and gave them a push. The two eloped, secretly moved to Tokyo, and started their newlywed life. They are grateful that their happiness now is thanks to Takuma. Then, as it happens, Takuma gets transferred and comes to Tokyo.