The Tokyo Hotaru Festival is back for a second round. This participatory art installation involves 100,000 blue LED light bulbs that will be floated down Tokyo's Sumida River.

It's sponsored by a consortium of parties including the Sumida and Taito ward offices, local tourism bureaus, the Tokyo Chamber of Commerce and the Tokyo University of the Arts.

Part of the Sumida River Renaissance Project, this nighttime event invites people to release floating solar-powered LED lights called inori-boshi (prayer stars), along the river.

The bulbs, which, upon touching water, light up, are meant to spark people's imagination by making the riverfront area reminiscent of the pre-industrial Edo Period (1603-1867), when fireflies were abundant. All the lights will be collected by fishing nets downstream after the event. People wishing to participate need to buy tickets (¥1,000 for each LED light) by Friday. The lights cannot be taken home.

The Tokyo Hotaru Festival will be held from 7 p.m. till 9 p.m. on May 25 at the Sumida River Terrace, the embankment between Sakurabashi and Azumabashi bridges close to Asakusa and Honjo-Azumabashi stations. For more information, call (03) 6825-7913 or visit www.tokyo-hotaru.jp (in Japanese only).