The Swordsman's End by Travis Giovanne Henneghan

Experience the beginning of The Swordsman's End Series! The Swordsman, Deem Swordfish, has finally returned to his home on Murmur Island to say his goodbyes to his family at Nihaoshoto Temple. But when he returns he discovers a terrible secret and must decide whether to confront an old rival of his to settle the matter once and for all. A mercenary group, The Ballistics, stands between him and his rival as his personal guard. Will he leave as he intended or will he finally settle the score?