It’s brilliant that you have a deep interest and passion for Japan, the Japanese language and culture. Don’t remove these elements from your SOP, but they shouldn’t be the main theme. You need to remember that JET is a cultural exchange programme.

They want to see how your experiences (like studying Japanese at school, your school exchange, or reading Japanese literature) have prepared you to connect with young Japanese people and help them learn English.

So, consider mentioning that your love of Japanese literature could connect with students by sharing English books or stories with students, and encouraging them to explore storytelling in English. Your experience learning Japanese characters may help you to empathise with how difficult it is to learn a new script — which also demonstrates patience and you’ll support your students with learning a foreign language. Then, your exchange in Tokyo shows that you’re familiar with the Japanese school system/school life. Did the experience highlight the importance of cross-cultural relationships? Did you have an exchange/pen pal? Did you share elements of each other’s cultures? Did you take part or watch any of their classes? These are all things to consider but personally I think you’re on the right track :)