What is this cutting instrument Tomoko has, and is she supposed to have it at school?

Question

In Fail 20: I'm Not Popular, so I'll Make Preparations, Tomoko has some kind of cutting instrument that I'm not familiar with. It's like a shaft-type thing with a retractable, squarish blade on the end. It's got me curious about what it is, but identifying it shouldn't be a difficult question, and I'm actually more curious about whether it's something that's normal to have at school. It doesn't seem like anyone else in the chapter is using one, just regular scissors. This makes me wonder if she's even allowed to have one. And considering what happens, it seems like Tomoko probably shouldn't have it.

Where I'm from, people are pretty paranoid about letting kids have sharp instruments. I had one teacher in middle school who didn't even trust us with scissors. And about the only time I had a knife was for cutting linoleum for a linocut print in a high school art class. I'm interested in the cultural differences here.

So, what is this item, and is it normal to have one at school in Japan, or is Tomoko in trouble?

Answer 1

That's a box cutter, more commonly known as a utility knife. I'm unsure exactly how common they are in Japanese schools, but they're certainly not prohibited: off the top of my head, Charlotte and Grisaia no Kajitsu are two other anime that depict box cutter-wielding schoolgirls (albeit in more sinister contexts).

In real-world Japan, there was an infamous incident in 2004 where an 11-year-old schoolgirl slashed a classmate to death using a box cutter. There were discussions afterwards about whether to lower the age of criminal responsibility, but I can find no record of any discussions about banning box cutters from schools, which suggests to me that there is a cultural element to their continued use, when other countries have banned them over far less.

(As an aside, I went to school in the UK and I do recall using box cutters during secondary school craft lessons, but they would have been rounded up and locked away with the other supplies after each lesson, and I'm pretty sure you would have been in massive trouble if you were caught walking around with one outside of those lessons.)