The abundance of plastic waste has increasingly become a problem of our time. The use of plastic has drastically increased 7 times in 2 years since the Covid-19 pandemic. Prior to 2021, 47% of 179 existing landfills in Indonesia were closed and replaced with new landfills which contribute to environmental problems such as greenhouse gas emissions, pollution of surface and groundwater, and air pollution (KLH, 2008 in Meidiana & Gamse, 2010). Plastics has emerged as an important and urgent area of study in Anthropology. The anthropology of plastic has a possible role in designing, intervening, and monitoring as a contribution to solve the problem of plastic waste (Pathak & Nichter, 2019). This paper is based on an experimental research from a voluntary action that I call ’30 hari merdeka plastik’. This study aims to understand why young people consume plastic even though they know the consequences of plastic pollution as well as to intervene through a collective pro-environmental behavior. Between August 2021 and April 2022, I conducted an online survey and in-depth interviews with young people aged 20-35 years with university education from any major. I then invited my research participants to get involved in the #30harimerdekaplastik social media challenge using Instagram and WhatsApp group. At the end of session, they were invited to reflect on the challenge they have participated in. During the 30 days challenges, participants were engaged in discussing what it means to consume plastic ethically with the awareness of what platics do to the environment. Interestingly, the influence of this movement is proven by the small pro-environmental actions taken by some participants during the 30 days challenge. The result is these small acts which have been consistent even 7 months after the challenge ended are influenced by social support and growing trust from participants.