It's not a pun, exactly, but I imagine a translation of her line could get quite a reaction:
"Is that rape?"
(Nanohana is Brassica napus, which is variously known in English as rape, rapeseed, or oilseed rape. As that last name may imply, it's raised for its seeds, which are pressed to make vegetable oil; certain varieties get marketed as canola, because for some reason "rape oil" looks bad on a store shelf. If you grow the same plant for its root rather than for seed oil, it's called a rutabaga.)
Kaede hereI'm not good at making conversation to fill the air... And this person with me understands thatI'm traveling with Producer at the momentEven though the only sound here is the shaking of the train car... The atmosphere isn't a cold oneRather, this time spent in a laidback way is something I prefer--I can freely take advantage of this momentNot many words are exchanged... It's just a journey where we can look out the window and drink, butIt certainly feels like a comfortable couples' trip... I'm really enjoying itBy the way, when Kaede tries to start a conversation here, it goes something like this:Ah... Are those nanohana, I wonder? Fufu...♡
Nanohana nano kana?