Babies’ heartbeats sound similar but are different for each baby. We paid attention to these slight sound differences , made a system that “automatically” creates tones using the “timings” and “emphasis“ of each baby’s heartbeat sounds, and had their mothers listen to the only melody in the world sung by their babies.

Normally mothers would sing lullabies to their babies, but these are the lullabies that babies in the bellies sing to their mothers who feel anxious about childbirth.

Firstly, we provided an opportunity for doctors to talk with expectant mothers who feel anxious about chilfbirth. During the interview, they were hearing the echos of the babies' heart sounds (at this point, we didn't let the mothers know that the echoes were being recorded). On a later day, we let them listen to the melodies (lullabies) created automatically from each baby's heart sounds as "the messages from your closest person."

The film was shared around the world across the border. As of January 15, 2016, it was played 1,720,706 times in 10 countries including Japan.

The film was highly rated as “a movie that makes mothers feel strong and positive about childbirth,” and gained trust among many expectant mothers. It helped greatly increase likability for Unicharm, a diaper manufacturer.