Things have been peaceful for Red Blood Cell when suddenly an abrasion occurs before her eyes. The White Blood Cells (Neutrophils) arrive to battle the bacteria and viruses invading through the wound, but they struggle against enemies like Staphylococcus aureus. Will the White Blood Cells (Neutrophils) find a way to defend this body?

The enemy disguising himself as a common cell has revealed his true identity. He is Cancer Cell. To protect this world, White Blood Cell (Neutrophil), Killer T Cell, and NK Cell must now confront the attacking Cancer Cell in battle.

Red Blood Cell is being chased by a germ! The one to come to the rescue is a masked Monocyte. Apparently, they are also part of the White Blood Cell family and a type of Immune Cell. There’s no way Red Blood Cell could be attacked by bacteria twice in one day, but she encounters another one on her way to the nasal cavity. The germ turns out to be Staphylococcus Aureus. They usually just exist on the skin and pores. But this time, they have a secret plan. What could it be?

The world (body) is engulfed in sweltering heat. Even after triggering sweat, the body can't be cooled down. Abnormal increased vascular flow, soaring fever... That's right, the body is suffering from heat stroke! Taking advantage of the situation, the Bacillus cereus is rampaging to his heart's content. Reeling from the effects of heat stroke, the usually reliable White Blood Cell (Neutrophil) is suddenly unable to perform... Isn't there any way to save the world from further global warming?

"We have detected life-threatening damage!" Hearing of this emergency, White Blood Cell (Neutrophil) rushes to the blast area. But there, he finds no traces of the blood cells he's supposed to protect! Due to massive bleeding, a huge amount of blood cells have already been flung outside the wound. And the bleeding continues... The situation grows more dire every second, but to protect this world and to save her friends, Red Blood Cell continues to deliver oxygen with Li'l Kouhai Red Blood Cell. Their world is on the brink of destruction... What kind of fate lies ahead for the cells?

Special Collaboration Episode with Otsuka Pharmaceutical's Pocari Sweat About Hyperthermia.

One day, while White Blood Cell (Neutrophil) is busy exterminating germs, he meets Backward Cap, a Platelet who wears her cap backwards. She is secretly training to become a stronger Platelet. However, a huge rumbling noise suddenly echoes inside of the body followed by violent shaking.

The antibody information of a cell has leaked. There is tension in the air after NK Cell makes a comment to White Blood Cell (Neutrophil). The journey to reunite the lactic acid bacteria with their friends takes the group to the large intestine. In the intestine, which has been irritated due to toxic gas being released by harmful bacteria, the group meets up with Memory T Cell who was formerly known as "Killer T Cell."

The most formidable foe has returned... Cancer Cell has reappeared, and harmful bacteria are wreaking havoc in the intestinal environment. With the body being in unprecedented danger, White Blood Cell (Neutrophil) and his comrades fight a bloody war to protect the future of the world they live in.

"Stop it, Cancer Cell!" White Blood Cell (Neutrophil) and his comrades confront Cancer Cell, but Regulatory T Cell obstructs their fight against the enemy! Meanwhile, Ordinary Cell, who had risked his life to save lactic acid bacteria, finds himself in the clutches of harmful bacteria! What fate awaits this world and the cells that live in it?