Zengaku! ~Zenra Toukou Shuukan Tokubetsu Taisaku Gasshuku~

Naked Week. Just as the name implies,
that is a week which you must head to school... naked.
A traditional custom of a certain Japanese academy.
However, the freshgrads that have only just enrolled
cannot handle such a high-level of exhibition straight away...
They must first head of to a special training camp so that
they may prepare themselves for the humility of nakedness.

That is, the Special Training Camp for a Naked Week regime.
Also known as... ZENGAKU!!

You participate in training camp with the girl that you adore!
But what awaits you at the camp is...
a full on training regime of humiliation and disgrace!?

[From DLsite English]