White Blood Cell U-1146 saves an average Cell from a Cancer Cell, and the Cell tells him that there are even more Cancer Cells in his apartment complex. Along the way, they run into both Killer T Cell and NK Cell. Unfortunately, these two do not get along at all, since they have such similar jobs… The resulting brief fight is a build-up of small funny moments, where Killer T Cell walks away to speak with some Platelets, borrows a bucket, fills it with water at the stream, and then dumps it over NK Cell’s head. The two go back and forth, jabbing and kicking one another while saying things like, “Oops, my hand slipped!” or “I apologize! My elbow slipped!” Their fight escalates quickly from there, but the initial humor comes from the unexpected appearance of their battle. While nothing really comes from their moment of combat, it is still funny to watch!

One of the many running gags in Hataraku Saibou is when Red Blood Cell AE3803 gets lost. Eventually, she decides to circulate through the whole body successfully on her own – though she does have some help from an unseen follower! U-1146 secretly stays nearby, even going so far as to return items she dropped and kill off germs that were threatening to attack her. This episode is funny because of the lengths that U-1146 goes to in order to avoid being seen by AE3803, since she is determined to navigate on her own. There is even an endearing moment at the end where AE3803 meets up with U-1146 to tell him about her day, and he listens excitedly, proud of what she has accomplished.

Naive T Cell has been struggling to live up to the expectations of the other Killer T Cells. He has been afraid of the germs that the rest of the Cells seem so eager to fight off, and he believes that he will reach their level of strength. But once Dendritic Cell takes a moment to encourage Naïve T Cell, the young cell transforms into an Effector T Cell, with sudden immense strength, courage, and a lot more hair! The transformation itself is hilarious, making the resulting Effector T Cell into a muscled character, almost styled like a character from Jojo’s Bizarre Adventure!

Despite AE3803’s terrible habit of getting lost, she is assigned as a mentor to young Red Blood Cell NT4201. At first, AE3803 is excited to become a mentor, but she quickly finds that her young protégé knows the ins and outs of their job better than she does! AE3803 tries to teach what she does know, which includes introducing her pupil to U-1146 as he is in the process of killing a germ. This particular scene is hilarious, as AE3803 tries to convince NT4201 that the White Blood Cells are not scary, and asks her friend to share a little about his daily job, even as he is stabbing and fighting off a germ as they speak! AE3803 clearly has some struggles as a mentor, but she does end up teaching her charge a few things in the end.

Of course, the funniest moments from Hataraku Saibou stem from AE3803! Her reactions to different dangers and events are hysterical, especially with her screeching screams. The way her face is drawn during these moments adds to the hilarity, as it is often erratic or ridiculous. For example, in episode 1, when she runs into the rogue Pneumococcus again, she screams and even her tongue screams with her! Her crazed voice is most commonly heard when she gets lost or yelled at, adding to that running gag. Honestly, AE3803 is a goldmine for the comedy of the series, and Kana Hanazawa does a great job of voice-acting for the character.