Tsuuhan de Katta Youtou ga Gachi Datta: Tameshigiri shitara Kuukan ga Sakete Isekai ni Tobasareta Ageku, Densetsu no Yuusha dato Kanchigai sarete Komatteimasu

The Cursed Sword I Bought Online Turned Out to Be the Real Deal! When I Tried to Slash, Space Split Open and I Was Transported to Another World, and Then I Was Mistaken for a Legendary Hero, and Now I'm in Trouble!