Ore to Norainu no Waltz

Daichi Tsukada—a serious, skilled cook who works as a salaryman—crosses paths with Tadaomi Waku, a man who has just been dumped by his live-in girlfriend and is absolutely famished. From that day on, a routine develops: Waku drops by whenever he pleases to get a meal, and in exchange, he serves as Daichi's sexual partner. Yet, no matter how many times they share their bodies, the only things Daichi knows about Waku are his name and his age. Burned by past romantic failures, Daichi has become overly cautious about maintaining emotional distance; he is terrified of asking about Waku's past or attempting to define exactly what their relationship is. Then, suddenly, Waku stops showing up altogether...

(Source: Gentosha, translated)