The Japanese have a knack for putting hard-to-describe feelings into words. A good example is the word "mottainai," used when expressing regret over wasting a resource or opportunity. It's an expression that's getting good use recently, as society makes a push to be more eco-conscious.

This weekend's Mottainai Festa combines such eco-consciousness with a love for festivals. The Mottainai Campaign, which organizes the event, was established in part by the late Nobel Peace Prize winner Wangari Maathai, who won the honor for her work on sustainable development as a path to peace.

During a trip to Japan in 2005, Maathai expressed that the term "mottainai" echoes the core of the philosophy she's working to spread; the importance of reducing waste, reusing finite resources and recycling. Since then, the term has become an international slogan in promoting sustainability. Subsequently the Japan-based group has expanded to work with local governments, schools and NGOs to promote an environmentally friendly philosophy, in addition to organizing the yearly festival.

Mottainai Festa offers something for everyone over a two-day period in Akihabara with craft workshops, handmade goods, a farmers market and musical performances. A pair of flea markets — one operated by adults, and one allowing kids to sell old goods — are likely to draw extra interest. Past years have seen not just your average secondhand wares, but also gadgets and anime treats, proving green living can benefit everyone.

Mottainai Festa takes place at Akihabara UDX in Chiyoda-ku, Tokyo, on June 29 and 30 (11 a.m. to 8:30 p.m./5 p.m.). For more information, call 03-3384-6666 or visit trx.jp/mottainai-fes2013/index.htm (in Japanese).