Visit Shirekoto in early April?

Hello,
I am planning a trip to Shirekoto national park in early April for about four days. However the visitor centers are closed until late April.
1. Can I still visit Shirekoto National park when the visitor centers are closed?
2. Are there any hiking trails open in early April?
Thank you
Linda

It is a bad time for visiting Shiretoko, because winter is ending but spring hasn't started yet. Many trails won't be open yet.

The visitor centre will be open - check details here: https://center.shiretoko.or.jp/
There are walks accessible in winter/spring from the visitor centre - you can rent some gear (boots, walking poles) from there too. https://center.shiretoko.or.jp/walking/
To access the national park, you can book a guided tour (e.g. snowshoe) using a local guide (no public access otherwise in Winter) - for a list of guides see here: https://www.shiretoko.asia/