[quote=Sho Minazuki]
I also doubt the school would let you bring weapons too.Somewhere outside of school is the best option.
[/quote]

I will agree on that, however, there are a few loopholes which allow the characters to bring weapons to school.

First off, sword/katana users can bring a nonlethal sword to the building for kendo club and store it in the teams club house.

Bow users can join archery club and bring their own bow and arrow to school, and store it in the club house also.

Spears and Staves can start off as props and be taken to drama club and stuff. All these weapons can be upgraded and such.

Sledgehammers... I've got nothing, but I do have a good idea. When characters have access to the velvet room, they can improve their weapons through Henrietta while retaining the prop weapons. Also, Kato can probably sneak a pipe easily by the school.