Hanappe Bazooka

Has Kazuo Koike as the creator of both mangas. He made Hanappe Bazooka with Go Nagai as the artist before creating Mad Bull. Mad Bull has the same kind of humor, violence and sexuality. 

Kekko Kamen made various cameos on this. The same studio animated both OVAs, both mangas created by Go Nagai and it countain the same perverted humor. 

The hero is perverted like Hanappe Yamada. It's vintage and has sexuality. 

Both are created by Go Nagai. Have similarities concerning the humor and are about demons. 

There is succubus and demons engaging in sexual activities. 

Summoning, Succubus, boobs and tons of ecchi. The MC remind of Hanappe Yamada. 

Same reasons than the first Devilman OVA. The voluptuous Sirene has inspired Mefist Dance and made a cameo. 

Go Nagai created both. Devilman and others characters made a cameo. The concept is similar except Devilman is about demonic possession and Hanappe Bazooka about summoning. It's obviously more comedic than Devilman but this OVA unlike the manga is more inspired by Devilman especially concerning the bullies. who chases Hanappe. 

I think Ai City is simmilar to Hanappe Bazooka in terms of weird story and weird humor. Both are kinda magic. 

Both are dirty and weird, and have man beasts. 

That ending looks oddly familiar, they both involve demons and sex  

Both MC use their fingers for throwing their powers. Countains demons and a vintage atmosphere. 

Same creator. Grendizer made a cameo and the demons are implied to be aliens too and use spaceships and UFO. 

Similar in story type and animation. Hanappe is better in character design, but stories and overall off-the-wall style are identical.