2nd Bonus Game from https://fantia.jp/posts/346666 This is a continuation of https://e-hentai.org/g/825919/d7e2ae38ae/ featuring the main character Saki Haruka and the other members from her Idol Group.

I don't understand much japanese but as far as I can tell the basic plot is that Haruka is volunteered to participate in a 26 hour long charity event where her block is a 100km run.

She is sponsored by a sportswear company and is contractually obligated to only wear their clothes and not change into anything else. Part way through the run the white portions of her sportswear become transparent and it is revealed that this is a part of the challenge to see if Haruka will continue to run despite her scandalous appearance.

Later in the marathon Haruka hears an odd sound followed by a rip, as her clothes disappear into the wind behind her. The announcer suggests that this accident is most likely due to the new transparent material must have become weak due to the long exposure to the sunlight. Everyone assumes that this is the end of the marathon and that Haruka will retire. Flashbacks of the previous game are shown and Haruka decides that if she gives up now then all her hard work would have been for nothing, and she continues running.

After a while Haruka is notified that the ending time for her run has been shortened and that she must pick up the pace and skip some breaks. On top of that as a prank Haruka's drink was replaced with a Diuretic, in order to get her to pee. The effects kick in and Haruka desperately needs to use the bathroom.

She thinks to herself that she can just find a spot behind a tree or bush during the next commercial break, and then an announcement comes. The marathon is such a success that they have decided to broadcast the rest, uninterrupted. Unable to hold it in she pees while attempting to run the rest of the way. She contemplates giving up but has a second wind and continues to finish the run.

With the spectators now cheering her on for her determination, Haruka finishes the run and gains the respect of the viewers for her dedication to the charity.