During Chapter 4
, you'll be able to access the west-end district
. Just north of Ried's mansion
, you'll be able to access a building that contains a Pure Water
item inside it. However, this area is guarded by a level 27 vampire and if you fail to kill it, the civilian Kimura Tadao
will die which doesn't affect much aside from his investigation, however, if you're running a 'Not Even Once
' playthrough you must be extremely careful as you'll most likely be under level 20 here.
Now that you have the water, head on back to the hospital and feed the plant. Sleep for 3 nights in a row until the plant grows and interact with it for the achievement/trophy.It is highly recommended that you make some sort of back-up save as sleeping 3 nights will cause the civilian population to contract illnesses, making the game more difficult.