Levi's hair has been as it is since he can remember. There's nothing special about this particular hair style. Only that it's neat enough that he doesn't have to be bothered by it constantly while keeping his appearance appropriate enough when the occasion calls for it.
Though there is one problem that he has to endure: cutting it when it grows far too long.
And Levi didn't feel comfortable having someone else do it. To him, having someone invade his personal space with a blade in hand is not enjoyable. And there have been chances when he has surrendered himself to a barber or two. Neither of them had found the experience to their liking.
Therefore, he resorts to cutting his own hair by himself.
Snipping off the bangs to level his eyebrows is easy. Trimming the back side never was. For someone capable of blades like himself, one wouldn't expect him to cut himself with them. But the task makes it hard for him to avoid doing so. He has cut himself on the scalp or finger and still, the hair on the back still looks uneven to him. And that frustrates him.
Corporal Levi didn't want to consider asking for someone's help again. Until Petra knocked on his door suddenly, causing him to slip the scissor from his hand and scratch himself with it again.
Having heard the ruckus, Petra had entered without much permission. It was no effort for her to place in what was going on. And no effort for her to take the pair of scissors from his hand and offer him to cut his hair.
Levi was reluctant. But Petra was insisting. So, he gave her one chance.
After that day, he'd given her another.
And then another.
Until the time came when Petra had measured how long it took for Levi to be uncomfortable with the length of his hair, and brings herself to his room to cut it for him without him saying a word about it.
And Levi appreciated how neat and clean his hair feels after her touch.