This sequence is also shown in a gameplay video.
After CHECKPOINT 12 on the rooftop terrace outside Takamoto's offices, climb the vertical pipe to the right of the doors (when facing them).
When you reach the top of the pipe, jump to grab the metal shelf with the air conditioning unit. Traverse around to the front of the shelf and climb on top of it.
Turn toward the signs and use the magnetic grapple to pull the sign above the door down toward Lara so it forms a flat ledge.
Jump to grab the edge of that ledge and pull up. Cross to the other side, jump to grab the next ledge and pull up.
Climb the ladder to the platform above. (CHECKPOINT 13) Go around to the edge of the platform nearest the signs.
Use the grapple to pull the next sign down.
Jump to grab the horizontal bar, swing and jump to the ledge behind the sign.
Climb the vertical bar.
At the top, jump back to catch the edge of the ledge behind (i.e., point the camera at the ledge and jump forward). Pull up.
[Part 2 | Return to Japan Walkthrough]