Fate/stay night, Toaru Majutsu no Index Recommendations
The protagonists Shiro and Touma are both all about protecting and saving others regardless of any consequences. They both have limited amount of power but somehow manage to survive many fights against most powerful villains. The character constellation in terms of romances is quite the same, the protagonist is living with his main female compagnion and has another tsundere-type love interest which is more loosely connected.
Both are basing on magic, supernatural powers and fights. Characters of protagonists are identical: Shirou is similar to Touma, because both of them wish to protect all people despite of everything; Rin and Misaka are both tsundere.
Touma and Shirou are "normal" boys that have a sudden encounter with a girl and are dragged in a world filled with magic and battle. Both Touma and Shirou have similar personalities and will try to save as many humans as possible even if they have to risk their own lives; but luckily no matter how strong their opponent is, they always manage to survive.