Still to me, the park is a hideaway from the Metropolitan Tokyo, but it isn't today. I'm not sure whether I've been to the Park for seeing cherry blossoms or the flood of people.
Here are my checklist for hanami (花見: flower-viewing):
A cup of coffee: Tully's coffee shop is located at the entrance of Shinjuku Gate
Nice company: Don't be late!! Right, Tomi?
Lunch: I prepared Katsu (deep-fried pork cutlet) Sandwich - Katsu's special -Also, check untrustworthy weather forecast: Seeing is believing, or believing is seeing!?
Last but not least, don't bring alcohol, or don't get drunk too much: それが大人のマナー! Promise!!