This page gives the 302nd Air Group's operations on various days. It was the main operational Irving unit at Atsugi at that time among the several types it operated*, though Atsugi was also a training base. For this date though the chronology only mentions single engine fighter ops of the 302nd. The original source (per another page in this series) is said to be the "Maru Special Pacific Sea-Air War" series magazine/paperbacks.
http://scrapbook.ameba.jp/pico_book/...006122456.html
Morning of April 19 1945 19 Raiden (Jack) and 10 Zeroes of the 302nd engaged P-51's near or over their own field. 6 Raiden were lost: 3 downed, 1 while taking off, 1 written off, 2 burned. Adds to 7 but doesn't specifically say the one taking off is included in the three downed; burned I assume means on the ground; written off or 'ruined' not clear if air or ground. A Zero was also written off. 3 Raiden pilots were killed. Ground gunners claimed 3 P-51's plus 1 claimed in air combat (better Japanese speakers please feel free to comment on this translation).
*"Japanese Naval Aces and Units of WWII" by Hata/Izawa gives the 302nd's inventory a/o Mar 1 1945 as: 24 Raiden, 20 Zero, 13 Gekko (Irving), 12 Ginga (Frances), 7 Suisei (Judy), nightfighter versions of last two planes, and 5 'other'.
Joe