Ulysses: Jehanne Darc to Renkin no Kishi

Both have the same character that require a special juice from another character to boosted up his or her powers, except one is a bit romantic while the other one was a bit erotic, that would make the guys drool.  

Both have harem and supernatural genres, and both have the same main female character that requires some kind of liquid substance from their male partner to level up their fighting capabilities.  

In both animes, the girls, the main characters, activate their fighting powers by kissing a guy who is important to them. Couples in both animes risk their health to save their towns from criminals. Both animes have magical moments, but they are not too fabulous.