If the translator is correct they pollinated tetraploid Honda group Sudachi with diploid Yamane Yuzu pollen.
Then rised the embryo in vitro. Then checked the chromosomes number and triplods where selected, In 1997 they made selections of seedlings to choose something with taste between yuzu and sudachi. In 2001 they got new fruits, but trees were very high and with weak flowering, so they make second generation of seedlings and another sellection. In 2023-14 they selected tree with medium grow and heavy flowering. Cultivar was registered in 2015.