It's an economic issue. Many Japanese people's income levels have not increased over the past 30 years. But prices will rise. Car prices have increased by more than 50%. For economic reasons, light vehicles are preferred in the current Japanese economy. This is especially noticeable in regional cities.
Your question is interesting! Most people may purchase a light vehicle for economic reasons, but there are also reasons to choose a light vehicle due to Japan's unique circumstances of short travel distances and narrow roads. I think there is also a characteristic unique to Japanese people: ``I like compact things.'' Thank you for your interest in Japan🤗✨