Bleach, Busou Renkin Recommendations
Both of the main characters gain powers that they had never had before, as well as having a very similar female character to assist them both. Believe it or not, both anime surround the idea about the meaning of friendship. Also both of the main character use humongous swords due to the extreme power they hold in within themselves.
Both are Shonen Jump manga where the lead uses a sword, is taught the ropes by a mysterious woman, and fights evil monsters.
Both are about a guy that gets supernatural powers because a girl. It's based on the typical shonen morality (to protect the world, to not kill the enemies...), both have weapons that evolve and the battles are carried in a similar way. Also, the school group comedy is very similar.