Chrome Shelled Regios, Seiken no Blacksmith Recommendations
Both CSR and Blacksmith have male leads [ Layfon Alseif in CSR, Luke Ainsworth in Blacksmith ] that are almost otherworldy in their combat skill. Both of them are at their best with Katana, which is a weapon in both series that is held on another level to others when used properly. Overall the series are different in alot of ways, but the simple relation in characters makes the viewer feel some nostalgia when watching one and then the other.
Both main heros use magic katans, also it is similar by the feeling you get after watching it.