The scene where the Platelets try to carry a box down the stairs is just so tense in a cute way, and when they finally make it down, they are so happy with this tiny little achievement, that you can't help but feel proud of them!
Even though they don't get focus as much in the later episodes, the cameos the Platelets get are no less adorable, be it sweeping dried leaves in Dendritic Cell's office, or handing Killer T a bucket of water in his fight with NK!
And not to mention the adorable shot in the opening sequence, of the Platelet Leader sitting on Neutrophil's shoulders, brandishing a cute little shovel the same way he wields his knife. Aww.
The adorable ending sequence, where the Platelet Leader rides on Red Blood Cell's cart while bobbing her head.
The relationship between Neutrophil and Red Blood Cell is just endearing on many levels. They seem to run into each other by pure coincidence, all the time, but it's clear they've come to care very much about one another.
After the platelets and Neutrophil work together to seal a cut, Neutrophil is lying on the platelets' netting. Red Blood Cell comes down to him, bouncing to lie down next to him. He asks why since that wasn't her job. Red Blood Cell said she wanted to be the first to make sure he was okay, and thank him for saving their lives.
U-4989, U-2048 and U-2626 (seemingly close friends of U-1146) have their own endearingly goofy moments as well, like getting stuck in narrow gaps when they pass through walls. They're brutal killers, but they're also downright Adorkable.
In a way, the tough love the Killer T Cells gave Naive T Cell: as explained to him by Dendritic Cell. While at first, they just seemed to be jerks, turns out they always did believe in Naive and were trying to get him to push harder.
Dendritic Cell showing Naive the photos of his senpais, when they were awkward and timid Naive Cells, just like him!
In the aftermath of the Vibrio infection in episode four, U-1146 is clearly very tired and shaken from the battle, having defeated the lead bacterium with a very risky Eat Me maneuver. To help him out a bit, a fellow neutrophil comes over with a hose and cleans off all the cytoplasm he got drenched in, which is nice. Doubles as a Funny Moment for just how random it is.
After spending the whole episode having the other cells look down on her and talk crap behind her back, it's very satisfying to see Eosinophil be hailed as a hero and get the appreciation she deserves, after saving everyone from the giant Anisakis worm. Bonus points for them actually apologizing for their unkind behavior instead of sweeping it all under the rug.
It gets even more heartwarming when Eosinophil is about to march off to face the Anisakis, as the other cells try to talk her out of it, admitting that while they made fun of her, no one actually wants to see her walk off to an apparent Suicide Mission.
Macrophage being a nursemaid and preschool teacher to the young erythroblasts in the bone marrow. She's so sweet, patient, and caring about the little ones.
When AE3803 was still an Erythroblast and was afraid of the germs, and AA5100 offers her hand saying "If you're scared, then let's run away together!" No wonder AE3803 came to trust her and look up to her for help. Aww.
A flashback reveals a young U-1146 as a myelocyte, saving a young AE3803 as an erythroblast. He only has a rubber training knife, but he still stands up to the Pseudomonas bully in a Go Through Me moment. He delays the Pseudomonas long enough for the grownup Neutrophil to arrive and take out the menace, in Papa Wolf mode.
After Neutrophil saves them, Macrophage is right behind him. She asks if the kids are okay. They understandably burst into tears. Macrophage reassures them they're safe now.
AE3803 then thanks this onii-chan who saved her life, and the two of them part ways with "bye-bye"note said in English which AE3803 tearfully repeats several times.
In the Cancer Cell episode, pretty much a dark and tragic chapter, there's one moment that shines out: Red Blood Cell running into Platelet Leader, and greeting her by poking her cheek, which tickles her and causes her to giggle! Kawaii!
Red Blood Cell and her senpai get into a brief conversation, while still continuing to poke the Platelets' cheeks! And after the two RBCs say goodbye, the Platelets start poking each others' cheeks in the background!
In hindsight, NK Cell being cold and rude towards her fellow immune cells because she didn't want them following her and ending up in harm's way.
The adorable love-hate relationship between Killer T and NK: they're willing to go to great lengths to protect each other, but will laugh at each other geting blasted by antibodies. Vitriolic Best Buds indeed.
Neutrophil asking a defeated Cancer Cell if he has anything he wants to say before he kills him. For someone as normally ruthless and merciless against threats to the body as he is, this is a surprisingly compassionate gesture.
As the mortally-wounded Cancer Cell is venting out the rage and hate he's felt since birth, Neutrophil hears him out. He doesn't react with his usual rage and hatred, reserved toward enemies, at him, he actually even seems apologetic and understanding of Cancer Cell's plight, and quietly puts him out of his misery, explaining that Cancer Cell violated the rule of the body, and that he was only doing his job.
Cancer Cell stating that he actually feels glad about being saved by Neutrophil while he was disguised, as he never thought anyone would ever care about a cell like him.
Later, after the battle against the Cancer Cell, Neutrophil asks Red Blood Cell if she was the one who summoned the rest of the immune cells, and thanks her for the help, leading to her making the happiest smile ever and asking him what he was talking about. Embarrassed, Neutrophil says it was nothing.
The pure joy you see from Red Blood Cell after she completes circulation by herself is extremely touching.
"I did it! Finally... Finally, I... I managed to circulate without getting lost! I did it! I did it! Yay! Yay!"
Even better is when Neutrophil proudly looks over her after quietly, indirectly assisting her the whole while, before sitting down at a bench and letting her talk about her day.
And this happens after Killer T berates him for "chumming up" with regular cells. The next few shots are of immune cells and regular cells doing just that, while Killer T grumps about the whole thing.
The Platelets being huge fans of Neutrophil.
Platelet: Hey, do the "Die, you germ!" thing, yeah?
After seeing Killer T's past and that no-one expected him to become a real immune cell, it's kind of heartwarming to know that Helper T and Regulatory T came to acknowledge his hard work and determination even though he probably doesn't realize it.
Episode 10 just has such a cute moment of the cells having a good time at the nasal cavity, with Red Blood Cell enjoying some steamed buns, Ordinary Cells hanging out at the sauna, and the Platelets as usual being cute and posing in front of a cardboard cutout of the Neutrophils fighting germs!
In Episode 11, despite the situation getting worse and worse between the heatstroke and the blackout(fainting), cells still do their best to help each other. Among other things, U-1146 pours out a cold drink he was about to have to a pair of Platelets who couldn't reach the jug, gives them a piggyback ride to avoid them getting hurt in the crowd, and makes sure they stay safe with AE-3803 before giving chase to the invading Bacillus Cereus. No wonder they look up to him as a big brother.
In the anime, Leader-chan and Backwards-cap-kun are also seen taking turns fanning each other, as the cells that suffered the worst of it rest in a triage area.
Despite the seriousness of the hypovolemic shock chapter, seeing so many of the body's cells fighting hard to keep the body alive no matter what. From Red Blood Cell encouraging her kohai to keep on working and trudging through a blizzard to carry oxygen, to White Blood Cell fighting off invading bacteria, and the many tiny platelets struggling to cover the wound with fibrin. There's even a sweet, single shot of an Ordinary Cell holding their breath just so they can share some oxygen with another, already unconscious cell.
The arrival of the Transfused Red Blood Cells. At first they're confused at what is happening, as all they know was that they were kidnapped and put to sleep in freeze cells and they suddenly woke up in a new and strange body, then they're told there's an ongoing hypovolemic shock due a great blood loss... And immediately put themselves at work, because that body needs help. They end up saving the body.
In the anime, the first thing senpai Red Blood Cell does after the crisis is over is to check and see if Red Blood Cell is alright.
In the anime, the Season 2 ED contains a massive crowd shot of all the cells, all smiling and happy. Even Cancer Cell is there!
Chapter 14 deals with the enslavement of hair cells. After seeing the Mountain of Bodies of his comrades and how they endured slavery than sending other Neutrophils to die, U-1146 promises a kid hair cell that he will kill the Acne King and gave him a spare hat. And he did good of his promise. Becomes a Moment of Funny when the kid made the former wear his hat.
Chapter 20-25. The interactions of an Ordinary Cell and some tiny Lactic Acid Bacteria are this, with the ordinary cell saving the germs from drowning and growing attached to said bacteria. With U-1146 as their lookout and protector, both set out to return the bacteria to a suitable environment. The Bacteria return the favor, saving both men numerous times from harmful bacteria by calling on their allies.
In a twisted version of heartwarming, Cancer Cell sparing U-1146 from fighting him and says he would rather chat with his dear friend than killing him:
Cancer Cell: Let's talk reasonably. No more killing, okay?
Chapter 26. U-4989 and AE3803 interactions have a heartwarming moment when they met each other. It's shown that both are both worried about U-1146's mental health after the trouble from the previous arcs with U-4989 thinking of inviting the latter for a break.
Speaking of which, U-4989 cried Tears of Joy when AE3803 remarked on White Blood Cells as super-reliable, as it is the first time they are looked up to by a Red Blood Cell.
In the same chapter, U-1146 encouraging Backwards-Cap-Kun when the latter is doubting himself about doing primary hemostasis. He even silently encourages when he's tied up and can only watch the latter struggle in performing his job.
The squadron receives a present from an anonymous sender (really just Rhinovirus). The desperate look on Killer T's face to have gotten a "thank you" from a civilian shows just how much he wants to fraternize, but hides it (terribly) underneath his tough guy persona.
Ordinary Cell and the Immune System cells play a game of badminton together. Of course, Killer T tries to weasel out of it by proclaiming he's too tough and professional to hang out, but everyone sees through the facade quickly and he's left trying to excuse himself with a blush on his face.
"Just this once, you got it?"
In Chapter 11, the Common Cold chapter:
when his detector senses the infected cell nearby, U-1146 spots the Body Cell nearby and his immediate reaction is telling him to come stand near him for safety, due to the fact he knows danger is nearby.
Another Body Cell is seen during the Common Cold outbreak when it begins spreading around the body. In a brief background shot, this cell can be seen clinging to the exterior of the building, just out of range of the infected cells, with what appears to be a still-undeveloped child like Body Cell Clone clinging to his back. The Body Cells really do care about protecting their clones.
is just so tense in a cute way, and when they finally make it down, they are so happy with this tiny little achievement, that you can't help but feel proud of them!