Unaired episode bundled with the sixth Blu-ray volume of the Hangyakusei Million Arthur anime series.

Second season of Hangyakusei Million Arthur.

Inside the human body, roughly 37.2 trillion cells work energetically 24 hours a day and 365 days a year. Fresh out of training, the cheerful and somewhat airheaded Sekkekkyuu AE3803 is ready to take on the ever-so-important task of transporting oxygen. As usual, Hakkekkyuu U-1146 is hard at work patrolling and eliminating foreign bacteria seeking to make the body their new lair. Elsewhere, little platelets are lining up for a new construction project. Dealing with wounds and allergies, getting lost on the way to the lungs, and bickering with similar cell types, the daily lives of cells are always hectic as they work together to keep the body healthy!

The cells of the human body never rest for too long; there's always something new to do and learn every day. At least, that's what Hakkekkyuu U-1146 feels as he rushes to and fro, searching for any pathogens that could cause harm to the body. Despite his dangerous line of work, it's all worth it to protect the happy smiles of Sekkekkyuu AE3803, the platelet crew, his fellow neutrophils, and the other cells he meets along the way. In his latest pathogen-hunting adventures, Hakkekkyuu U-1146 discovers how important cells can sometimes make mistakes, and that not all bacteria are actually bad. Everybody has their bad days, but everything eventually works out when their comrades have their backs. In the end, it's just another normal day for these hardworking cells!