This is a macron or a kana?


"来てXまった" What is the X in following image? Whole context
:[https://www.pixiv.net/member_illust.php?mode=manga&illust_id=69471473](https://www.pixiv.net/member_illust.php?mode=manga&illust_id=69471473)

[![来てXまった](https://i.stack.imgur.com/9sqDs.jpg)](https://i.stack.imgur.com/9sqDs.jpg)




It's the hiragana character し

> 来て **し** まった




It's the hiragana character し

> 来て **し** まった

