WWII Imperial Japanese Navy Submarine School Trainee Graduation Badge in original presentation box

A World War II-period Imperial Japanese Navy commemorative badge issued to trainees of the Submarine School (Kaigun Sensui Gakko). The badge is designed in the form of a five-petaled cherry blossom (sakura) with a reddish-brown enamel finish. A raised, silver-tone metal representation of a submarine is superimposed over the centre of the blossom. The reverse of the badge is fitted with a hinged pin and C-clasp fastener. The item is contained within its original paulownia (kiri) wood presentation box, which features a black corduroy-lined interior. The lid of the box bears three columns of Japanese kanji characters in gold-coloured leaf. The inscriptions translate as follows: the right column reads Kaigun Sensui Gakko (Imperial Japanese Navy Submarine School), the lower left reads Renshusei (Trainee), and the lower right reads Sotsugyo Kisho (Graduation Badge). This specific type of insignia was awarded to personnel upon the successful completion of specialized submarine training at the Kure-based facility.