Isekai de Zenra Yuusha to Yobanaide

While bathing in a hot spring Runa Hatagami is mistakenly transferred to another world as a hero in a towel... Moreover, the goddess only gave her a weird "Hot Spring" skill and a high defensive power? She managed to get a bath towel with her skill, but she was still almost completely naked... Furthermore, she was put under a certain "curse" by a witch who is planning to resurrect the Demon King... The situation makes it impossible for her to return to her original world!?