Complex sentence: According to a legend, a man called Hachiro who was transformed into a dragon chose here for his home after long wandering, and the lake was named Hachirogata ("-gata " means"lagoon").
Split into simpler sentences: According to a legend, a man called Hachiro who was transformed into a dragon chose the lake for his home after wandering a long time. Thus, the lake was named Hachirogata ("-gata " means"lagoon").