Fushigi na Somera-chan

Both shows share the same weird sence of humor and are produced by the same company. Similar animation style and similar plot consisting of gag comedy and both are 3 minuite long episodes. 

Both are fastpased short comedy anime. They also have a lot of the same humor. 

These two anime have many similarities: genre (comedy/slice of life), producers (Seven/Dream Creation), a weird sence of humor and a short duration of 3 minutes. 

Cute nonsense humor that might take you a while to really appreciate. 

Both are extremely fast-paced anime with good comedy tho saiki is a lot better in terms of comedy, Fushig na Somera-chan is still very fun to watch.  

Keroro Gunsou is focused on alien invasion more or less and Somera-chan can be all over the place in terms of plot for each episode. Both shows are comedy based and share similar gags/humor. Some of the characters are similar personality-wise. Both shows are also a little sci-fi themed with aliens/magic. 

Short series with absurd gag humour, a very fast pace, and strange fictional animals.