I''s Pure

Both anime's are pretty much about characters who are unsure of their feelings for each other, although Ajimu Kaigan Monogatari is more serious than I"s Pure. I"s is based more on the perverted comedic style while Ajimu Kaigan Monogatari is based more reality ( if that makes any sense at all). Besides these two different styles, both are about two people who cannot give in to their feelings for each other...the female more so than the male. 

School-life romance and drama at its finest is what links these two anime together. Both animes but you on an emotional ride of the up's and down's of love! 

These two share a number of things in common: #1: Both are six episode (25-29 minutes per episode) OVAs. #2: Both are based on two different 15 volume manga series created by Katsura. #3: Both are romantic comedies, and both share many of the same character types. (FYI, a typically pathetic/weak-willed rom-com lead, a tomboy and a reserved 'dream girl'.) #4: Both are high quality productions; the artwork remaining faithful to Katusra's wonderful, ecchi style. #5: Both end each episode with extras, though the I''s Pure extras are far better than Ai's--the Pure extras focusing on its lead's perverted fantasies from the manga. #6: Both are incredibly under-rated, by MAL's shitty standards. If Giant Robo is worthy of over 8/10, these two are most certainly not worthy of close to 7/10 averages. #7: Both have been released on DVD in the US: Ai was released years ago by Geneon, and I''s + Pure got released by Viz last year. Also, I can't comment on how good of an adaptation Ai's OVA is, but the I''s Pure OVA is as good as you can expect a six episode adaptation of a 143 chapter manga to be. The execution (starting in the present, two years in, and then going back to certain points in the I''s story) was perfect and mostly only meaningless content got cut. read more 

Both are about high school loving. Iori is just like Aya. The main difference is more girls in Ichigo 100% 

Both anime have a couple of a boy in love with a beautiful pure girl who is becoming famous. 

Main characters Daisuke and Ichitaka have crush on a popular girl in school but are too shy. Althouth the boys are very similiar the main girls not so much. Iori is more of an goodie while Risa is a rebel. Also there is other girl that has crush on the main character.  

Both involve the problems of dating a Idol! They both also have a mature feeling to them. 

Same creator and similar character designs. Both are romance, I''s is alot more realistic though. 

Although Tomoyo is superior... it's essentially the same story. The main character goes with the school idol and everyone around her trying to tear them apart. 

Both ARE serious romance anime !