Ninja Ryuukenden

Two anime about a guy wielding an outdated weapon to fight inhuman creatures and protect humanity from some mysterious threat. Each shows progress (or digression, if you will) into a rescue-the-girl type of story, with a traditional final battle that should both decide the fate of all of us, and save the love interest of the protagonist. Also, for all Kawajiri fans, Ninja Gaiden should be on your list, it is pretty similar to what Kawajiri used to make. 

For those who do not know Ninja Ryuukenden is Ninja Gaiden. This is in case you are looking for animes based on old games, not to mention that both have references to certain Japanese things, such as martial arts. PT/BR:Pra quem não sabe Ninja Ryuukenden is Ninja Gaiden. Isto é para caso você esteja procurando por animes baseados em jogos antigos,sem contar que ambos tem referências a certas coisas japonesas,como artes marciais.