The Testament of Sister New Devil

Mio and Maria are Basara Toujou's new stepsisters. These two women, although initially appearing normal, are actually demons, particularly Mio, who is the daughter of the former Demon Lord. Basarais revealed to be a former Hero, the enemy of the demons. Coming to care for his new stepsisters, he decides that, instead of using his powers against them, he will use his power to protect them. Now he must protect them, not only against the heroes, but also from other demons.¹

Sexual Content

This would be considered an ecchi anime. For one, nudity and sexual content are found in the show, according to Crunchyroll.² Women wear short skirts, and cleavage is seen. Also, when Basara first meets Mio, it is in the bathroom.¹

"The uncensored version features a lot of nudity. Mostly naked breasts and buttocks."

"Full frontal nudity of women [is] often seen."³

Considering these facts, there is no reason that anyone ought to be watching it. This anime is in direct conflict with scriptural standards. People should be modest in their dress, but that's not the moral standard this show follows. There is no real moral standard for his show, at least not one rooted in biblical principles.

"And, behold, there met him a woman with the attire of an harlot, and subtil of heart." (Proverbs 7:10)

"[26] My son, give me thine heart, and let thine eyes observe my ways. [27] For a whore is a deep ditch; and a strange woman is a narrow pit." (Proverbs 23:26-27)

The Bible commands us to observe the ways of God, to keep our eyes away from looking upon evil, so that we might not fall into the ditch of a whore, or the pit of a strange woman.

Fantasy Violence and Demons

There is violence as well.² Not just violence, but violence that involves demons and magic. It would be hard to divorce the violence and these aspects relating directly to it. As mentioned previously, Mio and Maria are considered devils. Basara fights to defend Mio, true to his word.⁴ According to the Scriptures, a devil is one of Satan's angels, those who rebelled against God. To defend and protect a demon would be to go against the LORD Himself.

Additionally, Basara uses various "Power and Abilities".⁴ He has abilities from being a hero, but he also has a power called "Banishing Shift", which was passed to him from his father.⁴ Mio uses gravity magic to create a black hole, and can also use lightning and fire magic.⁵

The Scriptures tell us that witchcraft (which is magic) is a grave sin.

"[9] ¶ When thou art come into the land which the LORD thy God giveth thee, thou shalt not learn to do after the abominations of those nations. [10] There shall not be found among you any one that maketh his son or his daughter to pass through the fire, or that useth divination, or an observer of times, or an enchanter, or a witch, [11] Or a charmer, or a consulter with familiar spirits, or a wizard, or a necromancer. [12] For all that do these things are an abomination unto the LORD: and because of these abominations the LORD thy God doth drive them out from before thee." (Deuteronomy 18:9-12) 

These powers are not from God. We really should not be having anything to do with demons, their powers, or violence in general. "Ye cannot drink the cup of the Lord, and the cup of devils", says Paul (1 Corinthians 10:21). You cannot drink of both, only of one.

Conclusion

In Romans 12:9, we are told to "Abhor that which is evil; cleave to that which is good." If we hate these evil things—violence, demonic activity, immodesty, and witchcraft—then we wouldn't be entertaining ourselves with them. Let's abhor this anime and all like it!

Sources:

1. "Shinmai Maou no Testament." MyAnimeList,  myanimelist.net/anime/23233/Shinmai_Maou_no_Testament. Accessed 7/16/2025.

2. The Testament of Sister New Devil. Crunchyroll, crunchyroll.com/series/G67570P3R/the-testament-of-sister-new-devil. Accessed 7/16/2025.

3. "The Testament of Sister New Devil: Parents guide." IMDb, imdb.com/title/tt4219258/parentalguide. Accessed 7/16/2025.

4. "Basara Toujou." Shinmai Maou no Keiyakusha Wiki, shinmaimaou.fandom.com/wiki/Basara_Toujou. Accessed 7/16/2025.