Japan has been in love with yōgashi (Western-style sweets and desserts) for centuries.
It started from the very first contact with the Portuguese in the 16th century, from whom the Japanese adopted the castella sponge cake (kasutera), as well as confetti-shaped sugar candy (konpeito). The pace of yōgashi adoption accelerated once the nation reopened to outside contact in the 19th century.
Vanilla custard-based sweets have been especially embraced. Today, there are a number of custard-based snacks in Japan that are either unique or far more common than they are in their land of origin, such as the cream pan, a small soft roll filled with thick custard, and the cream cornet, a horn-shaped bread filled with the same custard. Choux pastries filled with custard are also widely available, as are eclairs.