Demon Slayer: Kimetsu no Yaiba, or just Demon Slayer for short, is a popular anime about a group called "Demon Slayer Corps" which goes around killing demons (hence the name).
Immodesty
There are some characters in this anime which wear inappropriate clothing. "Minor characters do show some cleavage" says IMDb.¹ They reveal, "A female demon in the Red Light District Arc is a prostitute, and wears a skimpy bikini-style outfit for many of her fighting scenes."¹
Apparently, the wives of the polygamous character, Tengen Uzui, wear revealing outfits.¹
"A woman in the Swordsmith Village Arc is briefly shown naked standing up in a hot spring. You can see part of her breasts and her entire bare buttocks"¹
This is not okay. The Bible says people are to dress modestly. Paul states:
"In like manner also, that women adorn themselves in modest apparel, with shamefacedness and sobriety; not with broided hair, or gold, or pearls, or costly array;" (1 Timothy 2:9)
Demonology
The demonology in this show is lacking. As mentioned above, there is a demon that looks like a woman. Biblical angels (and subsequently devils as well) do not have gender. Thus, it reveals misunderstanding in angelology and demonology.
Similarly, the show had humans becoming demons.² That is not how it works! The devils are fallen angels which came with Satan at his fall (Isaiah 14:12-15).
"And his tail drew the third part of the stars of heaven, and did cast them to the earth: and the dragon stood before the woman which was ready to be delivered, for to devour her child as soon as it was born." (Revelation 12:4)
Murder and Man-Eating
Murder is a major part of the show. Also, human flesh is eaten.² After the flood of Noah's day, this is what God said:
"Whoso sheddeth man's blood, by man shall his blood be shed: for in the image of God made he man." (Genesis 9:6)
Just a few verses prior, God told Noah that the animals were for meat to him. Thus, humans are not food.
Profanity
There is some language in this show as well.¹ The clear biblical command is for us to not use inappropriate language. Paul, writing to the church at Colosse, said the following:
"But now ye also put off all these; anger, wrath, malice, blasphemy, filthy communication out of your mouth." (Colossians 3:8)
It lists "filthy communication" as a sin. Because of this, we should not watch things with this "filthy communication" in it.
Conclusion
Despite this anime's theme of killing demons, it is not okay for Christians to watch. There are many things contained therein that would contradict God's clear messages found in the Bible.
Sources:
1. "Demon Slayer: Kimetsu no Yaiba: Parents guide." IMDb, imdb.com/title/tt9335498/parentalguide. Accessed 23 Jan. 2025.
2. "Parents' Guide to Demon Slayer." Common Sense Media, commonsensemedia.org/tv-reviews/demon-slayer. Accessed 23 Jan. 2025.