Shy And Embarrassed Usagi

Mamoru thinks of something that will cheer Usagi up and he takes her to an old abandoned mansion. Usagi wonders why he brought her to this secluded place. She thinks it is for romantic reasons and becomes embarrassed and shy.
Key Cel
Sailor Moon S Episode #91
The birth of a rod of love! Usagi's new transformation
Ai no rod tanjou! Usagi no shinhenshin