Tsuki Ni Ichido No Omeshi Agari summary:

Coarse guy Maki is invited out once a month by childhood friend, elegant businessman Sugimoto Shinji. Maki always feels a little uncomfortable at the fancy places Shinji takes him too, but he goes anyway. He knows that Shinji's had a crush on him for a long time, and though Maki is straight lately he's been getting annoyed whenever Shinji talks about his boyfriends...