Arakawa Under the Bridge x Bridge

Both are comedies whose humor stems from the character's absurd actions and the side-splitting reactions of the other characters. Both use similar facial expression in their gags. 

FLCL deals with a group of crazy characters and one of them is homeless as well, I think. 

In terms of its wacky and absurd humor. The animation is top-notch and the characters are lovable and entertaining. 

Tsuruoka, Yota are sound directors from both anime and both have episodes full with randomness and things that will make you laugh out loud. 

I get the same feel with their narratives. Kamiya Hiroshi is also seiyuu of both Ichinomiya and Araragi. 

Hiroshi Kamiya voices both protagonists (Recruit in Arakawa and Nozomu in SZS). Both are comedies and very random with highly unique characters. Arakawa Under the Bridge x Bridge deals with a variety of diverse people living under a bridge, while SZS focuses on the classroom (where hardly any teaching gets done- more distracted rants than anything else). Arakawa Under the Bridge x Bridge is a lot more focused on subject matter than SZS, which tends to highlight on a vast scale with issues such as politics, stereotypes, other anime, complexes, and such. 

Welcome to the NHK! and Arakawa Under the Bridge x Bridge both contain unique characters which develop throughout the anime. Welcome the the NHK! happens to deal with the hikikomori as the protagonist with a female character that reaches out to "save" him. In this same way, Arakawa deals with Recruit, heir to the Ichinomiya group, who believes he must go through life without ever becoming indebted to anyone in any way. Nino, the female character, asks him to become her lover after he ended up owing a debt to her after she saves his life. Both anime series have the male protagonist change over time and develop new ideals in their lifestyles. read more