Can he hear anyone in the hallway?

Nope.

Hm...

He doesn't have his magical rings. He doesn't have most of his spells, either, just cantrips... None of which are very helpful for stealth or scrying.

He still does, though, know how to pick locks, and how to sneak the mundane way.

He waits a little while, then goes to try the doorknob.

It’s unlocked.

Does anyone react if he eases it open?

Nope! The hallway is dark, but there’s enough light through the windows to see by. No one seems to be out here waiting to catch him in the act.

He checks the rooms nearest his, first.

Two rooms are unlocked and completely empty, one room is locked. Just around the corner, where he and Sasaki came from, is a sliding door that does not match the other rooms.

He investigates.

Instead of a room, there is another hallway.

There is one window, at the end of the hall, and one door to his left halfway down the corridor. Directly across from that door, on his right, there is a bed set into an alcove in the wall. A girl is sleeping underneath messy blankets in that bed.

...Interesting.

He softly moves toward the left hand door, keeping an eye on the girl in case she stirs.

She does not.

The door is unlocked.

He investigates inside.

It's a very large bedroom. The room is so large and contains so much artfully arranged furniture that it might take a while to notice the bed in it at all, directly opposite the door on the other side of the room. There are also dressers and wardrobes and a set of chairs around tables. There are many lamps, which all look to be expensive.

There are windows on the right hand wall. Also against that wall, directly to the right of the bed, is a desk that boasts a tall ornate mirror, some papers and ink pots, and a set of makeup that seems to have been recently in use.

Nobody in it right now?

Nope, all empty! (Those closets on the left wall look theoretically large enough to hide a person, but that would be unlikely and silly.)

He ghosts back out, looking for other places to explore.

He can go back downstairs, if he wants, past the large oil paintings again. If he pokes around, he'll find a very fancy dining hall and some parlors. These rooms contain fancy clocks which will consistently tell him that it is shortly before midnight.

Almost all of the doors are unlocked, with one elegant wooden exception in the upper floors of the European-styled wing.

He doesn't pick any locks yet. Those seem likely to have people behind them, and he's being careful right now.

He notes escape routes out of the mansion, then retreats back to his room to sleep very, very lightly, until whatever awaits him in the morning.

What awaits him will eventually be a light knock on the door, assuming he doesn't leave his room.

He doesn't.

He wakes up easily, swinging himself so he's sitting on the edge of his bed.

"Yes?" he calls.

The door slides open. His visitor is a maid, a girl in a plain black dress. She bows nervously to the maybe-ghost. "Good morning, sir. Miss Sasaki told me that the Master says you can eat food with the servants, if you want to. He doesn't have plans to meet with you yet. But, um."

She glances out into the hall, and then blushes slightly. "Um. Count Fujiwara said he'd like to talk to you at some point."

"I'm fine eating with the servants, it's alright. And I'd like to talk to - whoever will talk to me, really. Not right away, though."

"That's fine, I think. He has painting lessons with the Lady at 2 o'clock anyway, so maybe you can try to find him after that." She steps back out into the hall, bows again. "I can take you to breakfast whenever you're ready."

"Give me a few minutes, and I'll be ready shortly."