According to the passage, pilgrimage to Kasuga-jinja Shrine of 'Taiki' (The Diary of FUJIWARA no Yorinaga), they were distinguished as '15 Tonjiki and 500 Tsutsumiii;' they might be different food.
「台記」春日詣の条には、「屯食十五具、裹飯五百具」と書き分けられているから、別の物であったかという。