This craft essence is currently unavailable on the EN ver.Seaside Luxury is can be purchased from Dead Heat Summer Race! event shop.
Here is a list of servants & CEs that can be obtained for the duration of the Summer 2017 event part 1: Dead Heat Summer Race and part 2: Death Jail Summer Escape.
Rashoumon event (Ibaraki Douji event)
Murder at the Kogetsukan
Inheritance of Glory
5 Star Servants Tier List: Best Servants [5/9 updated!]
Saint Quartz Farming Guide
FGO Reroll Tier List [5/11 updated!]
Best Craft Essence: Craft Essence Tier List
How to unlock/maxing Irisviel (FGO Fate/Accel Zero Order event)
How to farm EXP cards & level fast
How to build an Arts team
Chloe Von Einzbern
Altria Pendragon (Santa Alter)
Tamamo no Mae