Plastics are used for various application purposes such as social infrastructures and consumables in recent society so that those are essential materials. Although the researches and developments regarding the carbon cycling via plastics have been vigorously progressed throughout the world so far, only 9% of discarded plastics (6.3 Gt) could be re-used as the recycling resources. Then, the bio plastics deriving from CO2 as a carbon source were researched, resulting in the many productions derived from the metabolites extracted from plants and microorganisms. However, the processes for the fabrications are time- and money-consuming and complicated. Then, up to now, the concepts of cell plastics have been proposed that the unicellular green algal cells could be directly used as carbon recycling sources. The cell plastics were progressed for modifying mechanical characteristic, endowing water-repellency and evaluating biodegradation so on. The researches and developments of the cell plastics aims not to the only replacement of the plastics derived from petroleum soon but to discovering new research seeds of the technologies relating the cell plastics such as efficient preparation of algal cells and environmental cleanup in 2050. Afterword, the researches and developments progress with fusions of each relating technology widely based on Life Cycle Assessment (LCA) including the production using CO2 as a carbon source and discarding the cell plastics.