(２１)
Fold the top left and right flaps to the center.
(２２)
Fold the flaps like this picture.
(２３)
Then fold the top downwards to make a crease at the dotted line.
(２４)
Fold the flap like this picture.
Then unfold it.
(２５)
Unfold the two flaps.
(２６)
Open the bottom upwards a little.
(２７)
Open the paper like this picture.
(２８)
Fold the top left to the center.
(２９)
Proceed with the next step while holding the paper like this picture.
(３０)
Fold the paper at the dotted line.
(３１)
Fold the paper like this picture.
(３２)
Then fold the top right flap to the center.
(３３)
Fold the top right edge in the same way while holding the paper like this picture.
(３４)
After folding the paper, it looks like this picture.
Turn the paper over as it is.
(３５)
Fold the top left and right flaps to the center.
(３６)
Unfold the two flaps.
(３７)
Open the bottom upwards a little.
Then fold the paper in the same way as the 27th step to the 33th step.
(３８)
After folding the paper, it looks like this picture.
