The sender is from Gifu  岐阜市, a city of about 400 000 people. It was an important city historically - "Control Gifu and you control Japan" was a common phrase during the Sengoku period (15th - 17th century). It is a centrally located city. For those who were trying to unify the country, Gifu was a desirable located to do it from.  The sender writes: Have you hard of Japanese onigiri? They are also called omusubi. They are made by squeezing rice into triangle and putting various ingredients in between. It is delicious!