WIT didn’t think this through.
The final season of Attack on Titan (Shingeki no Kyojin) has a lot to surprise fans with. Aside from various plot points, there was a seemingly small detail that got anime onlys thinking “what?”. In one of the episodes it was revealed that Mikasa has got a tattoo, which symbolizes her mother’s clan.
Turns out, Mikasa is a descendant of one of the most ancient clans in the Attack on Titan world and is related to the Azumabito family. The girl once mentions that her mother lost her home, and it was possibly because of her Asian origins. This detail wasn’t given a lot of attention in the series, but there is a scene in the manga, where Mikasa’s mother gives her daughter a tattoo. She says that this tattoo should be passed down from generation to generation, and that Mikasa herself should continue this heritage and pass it on to her children.
WIT studio decided to omit this scene, thinking it was an unimportant detail, which led to fans’ confusion when the tattoo was revealed in the adaptation.
Mikasa is hiding the tattoo throughout the entire series both in the manga, and the anime. However, the manga portrays the girl with a small bandage on her wrist whenever her arms are fully shown. Since this is not a common occasion, the anime decided to play this as an issue of secrecy: we haven’t seen Mikasa’s tattoo because the girl has never shown it to anyone except for Eren. But this decision led to fans being puzzled and feeling like this plot twist came out of nowhere. Besides, they mention the last episode of season 3 where Mikasa and her friends are on the beach, and the girl’s arms are on display, but… no tattoo!
This decision can be explained by the general treatment of tattoos in Japan. This type of body art gets side eyes in this country due to the association with illegal activities. Outlaws and Yakuza (Japanese mafia) used to consider tattoos a sign of loyalty to their clan. Even now this country is not very accepting of those with tattoos: some bathing facilities such as swimming pools can implement bans on this body art. That’s probably why WIT studio decided to remove Mikasa’s tattoo from the series.
Although we can understand why WIT got rid of this detail, it’s still unclear why Isayama (the author of Attack on Titan) didn’t really comment on this. If he knew it was important for the story and was leading somewhere with this tattoo, why did he let the studio just forget about it? This question has led some fans to thinking that maybe it wasn’t such an important detail and the author never planned to give it more attention.