Best hiking around lake chuzenji?

I'm looking for a short 2-3 hour hike around lake chuzenji. I unfortunately don't have more time than that. Any suggestions?

Multiple options but without knowing your hiking level it is hard to make a single recommendation. My first thought is to take the ferry to Chuzenji temple, hike to the Italian Villa, visit that and then return to the bus stop assuming that you intend to arrive by bus. That would only be about 4 kilometers of hiking and certainly you should have time for more so you could go further around the lake. But the lake is 13 km all the way around so it's likely you won't have time for the whole trip. You might consider just hiking further around and then taking the ferry back.

Here are some links which might assist you:
Ferry time table: http://chuzenjiko-cruise.com/timetable.html
Hiking trails on Lake Chuzenji: http://www.nikkoyumoto-vc.com/cgi-bin/cms/cms_res/file/000/001/1426743...
Rough map of Ferry Route: https://www.japan-guide.com/e/e3806.html

It is cold in this area and often snowy even in late spring. That might limit your options as well.