Manga editor Shihei Hayashi unravels the secrets of "Mel-chan." The erasable ballpoint pen is also behind its creation.

The development of color-changing ink was behind the creation of the Mel-chan doll!

On Christmas 2025, manga editor Shihei Hayashi gave his one-year-old daughter a Mel-chan doll.

"I had heard about Mel-chan through a video and had been curious about her ever since. One day, my daughter was staring at a child holding Mel-chan, and I thought, 'I have to buy this.'"

I looked through the lineup and purchased "Mel-chan, I Love Caring," which is recommended for ages 1.5 and up.

"She feeds him, takes him to the bath, and hugs him. Even though he's a baby who needs to be looked after, he clearly has the desire to 'take care of the doll.' I find it fascinating and adorable to wonder what the root of this desire is, and I can't help but observe him."

Mel-chan, born in 1992, is made by Pilot. Natsuko Doi of the Toy Division explained the background behind why this educational toy came to be made by a writing implement manufacturer.

"It all started with the desire to create an ink that would turn red overnight like autumn leaves, and developed an ink that changes color depending on the temperature. It's still in development for use in pens, but the idea of a toy came about as we wondered if we could somehow bring this amazing thing to the world. If you put a doll of a certain size in an environment where the temperature changes, you can see a dynamic color change! So, we decided on a bath! That's how the concept was decided, I've heard."

When Mel-chan was released in 1992, a doll that could be taken care of and bathed with was not common. The birth of Mel-chan, whose hair turns pink when exposed to warm water, was a development unique to Japan, where bathing in hot water is a common habit. Development of the ink continued, eventually resulting in the FriXion erasable ballpoint pen, which was released in Europe in 2006 and in Japan the following year.

Relationships and worldviews are built from reflections of children's lives.

"My daughter seems to be reliving her own experiences through playing with dolls. I think the human-like design is helping her learn about daily habits together with Mel-chan."

After the age of 1 or 2, when children start playing by recreating their relationships with their parents, by the time they enter nursery school or kindergarten, their relationships begin to expand.

Doi says, "When the first friend doll was made in 2003, it was called "Mell-chan's Friend" so that buyers could name it, and the following year "Boy's Friend" was released, but it wasn't a hit. When the Nene-chan doll was released in 2014, it became a huge hit because it had a name and was characterised as a younger sister," to which Hayashi, acting as a manga editor, responds, "I guess people like it more if the character has a clear personality than if they have the freedom to name it themselves. It's really interesting."

Doi continues, saying that the appearance of Ao-kun has expanded the popularity of the doll to boys as well. "The number of boys, which had previously been 1-2% of users, has now increased to 15%. I think that the desire for boys to play with the dolls is also due to a change in society, with more men taking part in childcare."

There are very few written rules in the world of Mel-chan, such as her height being 26cm and her eye contact when held, but one of them is that she cannot speak. Although the official videos feature voices, the dolls themselves are silent. The developers hope that children will use their imaginations to play with the dolls, which are set within a three-part relationship between the child playing with them, the Mel-chans, and the peripheral accessories that help with their care. The dolls do not even have set birthdays.

"I see, the fact that the day you bring them into the home becomes their birthday makes it feel similar to pets. They're part of the family. This is a different approach than creating a character and presenting it to users along with its worldview. I'm curious to see how Mel-chan's story will unfold going forward. I'd like to continue to closely watch my daughter play with it."

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