Hotaru which is the main event of The Japan Fair, organized to introduce Japanese culture to the community, so that more people are interested to know the Japanese culture. In addition, this festival is also a gathering event for the community of Japanese culture. Many of them came by wearing costumes typical of Japanese anime.

Festival held this year is organized differently. Visitors were divided into two groups: modern group and traditional group. After grouping, visitors can support their group by following various interesting competitions such as eating ramen, making sushi, making shaked salad, and other competitions.

Besides competition, visitors can also participate in many workshops. There are onigiri workshop, paper folding (origami), Japanese calligraphy, and several other workshops. While the competition or workshop, visitors can buy a variety of Japanese food on the culinary festival such as ramen, sushi, shaked salad, takoyaki, okonomiyaki, dorayaki, onigiri, and others.

There was also a live musical performance that shows many Japanese songs and anime. Cabaret cosplayers also entertain festival visitors.

In conducting Hotaru, UKJ also collaborated with Aikido and Kendo ITB. Both of Japanese sport units grouped into traditional group in the competition. Aikido demonstrated simple movements that utilize other forms of attack to conquer the opponent. Whereas in Kendo, a martial art is shown that using bamboo swords.