The To go menu "Matcha Zenzai" is on sale exclusively at the Tokyo Skytree Town Solamachi store in Giontsujiri. The price is 700 yen (tax included).
This is a matcha zenzai made by pouring carefully brewed Uji matcha into azuki beans and topped with fluffy azuki whipped cream, sweet potato kanro-ni, and shiratama. It seems to be a dish that is packed with the particulars of a teahouse.