Wow that's a tough one to synthesize, you may as well try to find a sample that sounds similar.
If you want a hand at synthesizing something similar I would first try to find a static synth sound that sounds similar to the end of the note. Then route an envelope to the cutoff of a filter, like a Peak or Band Pass filter that has the resonance turned way up to make the cutoff drop down rapidly with every note played.
Then the whole thing should be run through a drastic "telephone" EQ to remove most of the low and high frequency and give it that mid-rangey lofi quality.
But you're going to have to spend some time and experimentation to get it right.
PS: I really like that track!