Do you know about the old Japanese custom called “Okuizome” ? It’s the custom to make a baby pretend to eat food wishing the baby success on the 100th day after the baby is born. It is said that we’ve been having the custom since Heian era.
The ceremony is usually done at home and a little table is set up for the baby.
The main is tai (sea bream). Other foods may include umeboshi (pickled plum). sekihan (sticky red rice usually eaten during ceremonies), sumashijiru (a kind of clear soup), and nimono ( a dish of stewed vegetables). Sweets may also be included.
Sometimes they do the ceremony called ”Hagatame” at same time. It's supposed to help the baby develop strong teeth by biting a stone.