The late Wangari Maathai kickstarted the Mottainai movement in 2005, a year after she became the first African woman to win the Nobel Peace Prize on account of her political and environmental activism. The Japan-based campaign encourages environmental conservation and sustainable use of resources through a variety of means, ranging from custom vending machines to events like this weekend festival in Akihabara. There'll be a variety of booths propagating the Mottainai message – reduce, reuse, recycle, respect – along with flea market stalls run by children (1-3pm only) and some of the local otaku. Because, eh, toys need to be recycled too. Hang around on Saturday evening for a candle display, sand art performance by Karin Ito and music by industry veteran Tatsumi Moritoki.