In episode 21, there is a mild mention of puberty.

In episodes 2 and 3, Mametchi accidentally gets a bra caught around his chest.

In later episodes exclusive to Japan, a character called Himespetchi is deeply in love with Mametchi and expresses lovestruck behavior such as eying Mametchi in bed, fantasizing about marrying/kissing him, as well as screaming and blushing while dreaming or thinking about him.

Episode 236 features a comedic rape reference in which Spacytchi goes towards Himespetchi menacingly while she looks terrified; we then hear Himespetchi moaning in what sounds like a sexual manner and saying "It hurts!" in Japanese in a strained voice. Spacytchi is then shown and he appears to be thrusting, but it is then revealed that he is simply giving her a massage. Notably, the close-up shows Spacytchi moving his whole torso but the comedic reveal shows him only moving his hands.

Characters get injured for comedic purposes; usually the wounds look like big bumps but sometimes they look like blood smudges.

In one of the Halloween episodes, the characters imagine a ghost with blood coming out of its eyes and mouth.

Samurai Mametchi attacks villains with his sword. They collapse but no blood is seen.

No major profanity is used, but "Jeez" is used several times and the English word "sexy" is used in episode 232, despite this episode being Japanese exclusive.

In Japanese episodes, there is a trio of devil characters called the "Three Hell Sisters" but the word Hell is said in Japanese.

Additionally, Hell is mentioned in episode 7 in Japanese but this is changed to the word "underworld" in the English dub.

There is a place commonly depicted called "Waru Cafe". (Waru means bad). It resembles a pub and thug-looking Tamagotchis with sunglasses, scars, etc, are seen smoking and drinking various types of alcohol.

Kuromametchi is briefly seen holding a glass of wine in episode 16.

In episode 222 and onwards, an old man sells cider.

Somewhat frequent pictures and sounds that might be scary or frightening to young children. PEGI would say that it is not suitable for persons under 7 years of age.

One of the characters falls unconscious and seems to be dead as she falls through the sky (she is a flying character).