If you're looking for manga similar to Ulmatsu-san, you might like these titles.
Characters from various Type-Moon franchises, such as Fate, Tsukihime, and Kara no Kyoukai are able to hang out at the strange cafe called Ahnen Erbe. They chat together and deal with various curiosities such as a nosy talking cat or a "pot of happiness," which expels a gas that causes people to laugh.
A manga loosely based on the career of Go Nagai and how his most known works were born. It tells about Geki Nagai (a character based on nagai himself) who is struggling to break out of his typecasting as the go-to guy for gag manga by breaking into the sophisticated world of story manga.
The Robot Alliance dominates 90 percent of the universe, but one of the brave biologicks (organic organisms) — Sapphire, Princess Knight of Silverland — forms a band of space pirates to strike back against injustice!! Joining her in her rebellion are Leo of the planet Jungaly, and Sharaku, the Three-Eyed One.
A short gag "series" that Clamp draws in various magazines. Each involves xxxHOLiC and another CLAMP title.