Reach Rank 2 with the Death Confidant by starting Takemi’s request in the clinic
Visit Takemi at the clinic in Yongen-Jaya on available days
Choose dialogue options that show interest and support her work
Continue advancing her Confidant ranks until Rank 9
At Rank 9, choose the romantic dialogue option when prompted
Do not choose the friendship-only option if you want to date her
Reach Rank 10 to complete the romance route
Keep spending time with Takemi whenever her Confidant is available
Gift items only if needed; they are not required to romance her
Make sure your Guts stat is high enough to unlock her later ranks
Continue progressing the story until her Confidant becomes available again if blocked by progression