Oretachi Kyou kara Fuufu da yo? Toshishita Osananajimi to Amanure Shoya

"I'd be happy to marry you, but what's in it for you?" Yoo is suddenly proposed to by her childhood friend Tsukasa, who is six years younger than her, and they end up married in the blink of an eye. The marriage allows Yoo to avoid pressure from her parents and helps her out at work, too, so a sham marriage is good for her, but what in the world are the advantages for Tsukasa? (Source: Choco Love, translated)