The cap placed on the occasion of the Second Coming of Age Day celebrations in Beppu (a holiday dedicated to those who will pass the age of 20, the age of adulthood in Japan). The cover mainly promotes the hot water springs in which Beppu is famous. Beppus mascot, Beppon, whose head is actually the standard icon for hot springs in Japan, also appears.
Translation of the text on the cover: 山は富士 海は瀬戸内 湯は別府 - The mountain is Fuji, the sea is Seto Inland Sea, and the hot water is Beppu. ようこそ別府へ - Welcome to Beppu 平成28年別府・日出 二回目の成人式実行委員会寄贈 - Donated by Beppu/Hide Second Coming of Age Ceremony Executive Committee in 2016