The ice-cream flavor traditionally made with green tea powder in Japan is matcha.
Matcha is a finely ground powder made from specially cultivated and processed green tea leaves. When used in ice cream, it gives the dessert a vivid green color and a distinctive vegetal, slightly bitter flavor balanced by sugar and dairy. Matcha ice cream is a common modern use of the tea beyond the traditional whisked drink.
Matcha is not the same as hojicha, which is roasted green tea and usually has a brown color with toasted notes. Yuzu is a citrus fruit, while sakura refers to cherry blossoms or their flavoring, so neither is the green-tea powder used in classic matcha ice cream.