He is from the future; she, from the past.
It does not get any more complicated than that.
He has found a glitch in time, specifically and only on the Lunar Valentine’s Day, where he can visit this simple seamstress in 1930s Singapore.
His luck becomes somewhat an obsession and a lingering question to him. It helps form a friendship and maybe a deeper relationship between him and this seamstress.
But each visit he makes has irreversible consequences.
Will this friendship continue? Or will they close the book on this one?