The main reason Pirdan considered this Invention Mouse special was... it had developed self-awareness not long after it was born.
"Around the third day after its birth, it experienced its first bout of melancholy."
Melancholy belonged to the realm of emotion, and emotion was how all living beings perceived the outside world. The more complex the emotion, the deeper the cognition it represented. Melancholy was clearly a relatively complex emotion.
"After that, it took only one month to overcome the most difficult vocalization barrier faced by mice and learn to express meaning through throat sounds."
"Next, it took three months to learn the Pirus language."
"After learning the language, it gave itself a name."
At this point, Pirdan glanced at Pisi before saying softly, "It named itself... Naksu."
"Naksu?" Pisi froze for a moment upon hearing the name, then murmured under his breath, "Why does that sound somewhat familiar?"
Pisi frowned and pondered for a while. Then, as though something had occurred to him, he said word by word, "Nakfei?"
Nakfei? Naksu? Luigi and Angel were utterly baffled. The names sounded quite similar, but what special meaning did they hold?
Luigi asked directly, "What is wrong with that name?"
Pisi said, "Pifeifei's original name was Nakfei..."
With Pisi and Pirdan's explanations, Angel and Luigi finally understood what had happened.
Like Naksu, Pifeifei had developed self-awareness soon after birth. After learning language, she had given herself a name: Nakfei.
Later, however, the Pirdan family had felt that the name did not fit the Pirus style and changed it, which was how she came to be known as Pifeifei.
Naksu's experience was extremely similar to Pifeifei's. It had developed self-awareness early, named itself, and even chosen a name nearly identical to Pifeifei's.
Pirdan said, "That is also why I think this Invention