Romance wa Tsurugi no Kagayaki - The Last Crusader-

A young swordsman named Rune is strolling in the woods when he notices a lake. And bathing in the lake is the most beautiful girl he has ever seen. Suddenly, a wolf leaps from the woods and attacks the girl. Rune swiftly defeats the beast. The girl he saved turned out to be Cecil, the princess of Barran! Watching how the princess was taken back to the castle by a zealous knight, Rune swears that he will do anything to become worthy of her love. And his friends (all of whom happen to be girls) have no choice but to help him!

[From Mobygames]