Yesterday I went kayaking on Lake Shikotsu, with two friends. We joined a tour organised by Ootaki Outdoor Adventures.
It was so peaceful and beautiful - the lake was calm and it wasn't too hot. The water is SO clear you can see the sand, rocks and old trees on the bottom. We even caught shrimps, cooked them and ate them! And swam in the lake, wearing life jackets.
The kayaks were big and comfortable. We used long paddles and braced our feet inside the kayak to give ourselves more power.
Kayaking isn't difficult, and specially on a calm lake - anyone can do it. A few years ago I tried kayaking at Shakotan on the sea and that was more difficult with the sea currents and wind.
Now there are many kayaking companies - Shikotsu has at least 3 - so why not try it sometime?