Hataraku Saibou - Thymocytes

As Killer T Cell and Helper T Cell get into an argument about the former’s harsh training methods, Dendritic Cell shares his photo album with the Naive T Cells and explains the two’s shared past. While training in the Thymus, the future Helper T Cell and Regulatory T Cell easily passed all the hand to hand combat and obstacle courses, but the future Killer T Cell struggled. The future Helper T Cell was disdainful of him for this, but eventually gave him advice that helped him pass the final test. Killer T Cell vowed to become a worthy defender of the body while Helper T Cell decided to become a commander. In the present, Killer T Cell and Helper T Cell notice the photo album. Severely embarrassed, they both try unsuccessfully to take it from Dendritic Cell in order to burn it. Regulatory T Cell muses that they are both still morons as they were in training.