Mahiro Yasaka a male protagonist of the story. Usually avoids close contact with Nyaruko and often stabs her with a fork.
He reluctantly finds himself under the protection of Nyaruko. He tends to attack aliens by stabbing or throwing his fork whenever they make him angry. He appears to attack so fast that currently no alien has been able to dodge yet. At first he dislikes aliens and wants to kick them out, but as the story progresses he starts to become more tolerant toward their actions. He is attracted to Nyaruko (while she is in her human form), but dismisses her advances as he believes nothing good would come of such a relationship.
- He is the only character who does not come from a Lovecraftian work.
- Mahiro never attacked Hasutā