We have conducted monthly events related to astronomy and space science ( stargazing, making telescopes and rockets, chemical experiments, fields studies, etc.) for 21 years. We celebrated our 20th birthday by holding an event of the lecture on life in the universe at the Oshu City Cultural Hall (Z hall) in Oshu in 2013. The lecturer was Dr. Norio Kaifu of IAU president. And we reviewed the 20 years activity with many people before the lecture. About 60 children are supported by more than 10 leaders who are specialists of school teachers, astronomers, and amateur astronomers, etc. More than 800 children have joined our Mizusawa Z Chapter for 21 years.