Map number 23 (you can also get Kinpu, Mizugaki, Ryokami, Kumotori, and Kobushi). Description number 70
I hiked Daibosatsurei in the winter with my wife and son. They close the road to the main trail head in the winter, but there’s a free parking lot with access to the trail at 35.740325, 138.81164.
You could either hike up the mountain from this parking lot toward Marukawa-so, which is a hut on the ridge, or you could hike along the road for about a quarter mile or so until you reach a cafe. The trail is right behind the cafe and takes you to Chobei Lodge. Then you can take the trail straight up to the summit.
I would suggest making a loop out of it. So from the free parking lot take the trail toward Marukawa, which follows a stream for part of the way. The climb up is mostly uninteresting until you get to Marukawa where the view opens up just before entering a conifer forest on the ridgeline.
From here, it’s another mile or so to the marker for Daibosatsurei. Although the conifer forest and the light brushing of dry snow is serene, there isn’t much view because of the tree cover. But if you continue along the ridge for another 1000 feet or so the view opens up at a rocky outcrop. One of the benefits of hiking in the early part of winter is that you’re likely to have clear weather, and from the view is nice. There was a mischievous fox that doesn’t appear to be to weary of humans so don’t let him get your lunch.
You can take the trail down toward Fuku chan sou, then follow the road to Chobei Lodge. The trail back to the parking lot is on the other side of the road. Remember that once you get to the cafe, you’ll hike on the paved road back to the parking lot.
In the summer, you could probably cut the hiking distance by parking at Chobei Lodge.