Our stage this time is Lake Mashu, a caldera lake and its surrounds in eastern Hokkaido Prefecture. Our program host climbs Mt. Mashudake near the lake. On his way to the summit of the mountain, he comes across some summertime alpine flowers. After walking for about 4 hours, he finally reaches the summit, where a superb view overlooking Lake Mashu spreads out before his eyes. Later, we show you rare footage of a variety of creatures that survive in the plentiful spring water in the forest surrounding Lake Mashu.