In Nancy Drew: Shadow at the Water’s Edge, when Nancy asks for more information about the Ryokan, Yumi will clam up and not say another word until you retrieve her Bento boxes at her apartment at the Kurume station. She gives you her apartment key.
To travel from the Expo center at Matsue, take the trains to Iga, Kobe, Miyazaki, Urawa, then arrive at Kurume. Use the key to unlock the door.
Inside her tiny apartment, you must look at the shadow puppet book by the TV, read the paranormal book and find the contact information for Savannah and notice the torn pages. Then you will be able to check off the item “Explore Yumi’s apartment” in your task list.
You’ll find the Bento boxes on her counter. At this point, you can leave the apartment, but there are plenty of other fun things to look at. In her closet, you can translate her sewing equipment to reveal dyes, pick up the unmarked DVD, open her window, read Kasumi’s letter off of the shelf, notice the frog safe with a four-character combination lock, notice her TV has an Avatar app that is locked with a color-grid password, and play the DVD on her TV. Be sure to ask Yumi about the DVD later.