Marine Corps Air Station Iwakuni hosted friendship day May 5, 2016. Since 1973, MCAS Iwakuni has conducted a single-day air show and open house specifically designed to foster positive relationships between the air station and our Japanese hosts. The event offers a culturally enriching experience that displays aviation performances, demonstrations and provides food and entertainment for guests of the largest single-day event in Iwakuni. - Marine Corps Air Station Iwakuni hosted friendship day May 5, 2016. Since 1973, MCAS Iwakuni has conducted a single-day air show and open house specifically designed to foster positive relationships between the air station and our Japanese hosts. The event offers a culturally enriching experience that displays aviation performances, demonstrations and provides food and entertainment for guests of the largest single-day event in Iwakuni.