Follow the life of Tadayasu Sawaki as he enrolls in an Agricultural University and learn about bacteria and viruses that he alone can see with the naked eye.
Before returning home, Sawaki and his friends meet Marie once more and learn that the messages left by the microbes helped her family to resolve their differences and move on with their family business. Finally back at Japan, Hasegawa wonders about what she should do from then on, as with her engagement cancelled, there is no reason for her to remain at the university, but Sawaki encourages her to move on with her carreer not for obligation but for doing what she really wants to.
