Tetra knows all the hiragana by the time she returns

Tetra goes to the Tokyo Skytree observation deck

Tetra encounters and purchases onimai merch

Tetra looks out a window from the top of >=5 of the buildings in "List of tallest structures in Tokyo" wikipedia article

Tetra looks out a window from the top of >=10 of the buildings in "List of tallest structures in Tokyo" wikipedia article

Tetra looks out a window from the top of >=3 of the buildings in "List of tallest structures in Tokyo" wikipedia article

Tetra goes to a place that is both a tea shop and a disco