Haha I know those places.
I wonder when the trip is; Tokyo and Osaka get much more unpleasantly hot than Hawaii, but if it's like June then probably still cool-ish in Japan.
Man, flying from Japan to Hawaii for just two days, ouch.
There's actually a Shinto shrine in Honolulu! But not too close to Waikiki and Ala Moana, it's on the far edge of Chinatown. (Yes, Chinatown.)
Sakurako asking permission to share Kasumi's bed rather than it happening naturally, "skipped a step" regarding honeymoon, compared to the other couple buying rings...