Kamikochi has started their service (the road, busses and some hotels) of this season since April 20th.
I heard the current (April 20th) situation of routes from Kamikochi to Tokusawa from a city officer who is working for Kamikochi Alpine Hotel, Tokusawa Lodge and Yakedake Hut.
He said, some portions of walking trails in Kamikochi are still covered with snow, so if you want to walk further than Kappa Bridge, you need long boots or snowshoes. Snows on roads for special cars for workers in Kamikochi has been cleared away, so if you don’t have such shoes, be careful walking on such roads (see the right photo). Even in that case, I recommend you wear waterproofed trekking shoes.
Refer to a blog article in Nagano Prefectural website “Go! Nagano”, which has been redecorated this April, and Facebook Kamikochi Page.
The right photo is Kesho-yanagi (“cosmetic willow”), special trees in Kamikochi, trunks of which are coloring with pink in winter.