Advice on fire insurance for newly bought home

I am closing on a second hand house in a few days and the real estate agent says I need to get fire insurance (kasai hoken).

The agent proposes a contract with Tokio Marine Nichido, but it is a 5 year contract and I need to pay upfront around 900,000 yen. Is this a fair price? Any advice? I'm not sure going for the absolute cheapest is the best option either as I'm not sure all insurance companies approve/deny claims in the same way or not.

One more question, is it a big deal if I don't get the insurance from day 1 but apply later? (Ignoring the risk of a fire occurring during those days obviously). E.g. would the fact I applied not on the day I became the owner cause them to not cover certain things (with the reason being I could have damaged them between moving in and getting the insurance) Or is there a legal requirement to get the insurance?

Any advice/recommendations welcome.

by big-house-tokyo