The Otherworlder, Exploring the Dungeon, Vol. 2 (manga)

Struggling to get a grip on things after his resource gathering mission in another world goes horribly awry, Souya opts to sell off his firearms in exchange for a bow. To learn the ins and outs of his new weapon, Souya tracks down a pair of elven sisters who can teach him what he needs. Unbeknownst to him, however, they come with some baggage of their own...