Tell the Japanese name of the set which card "Fellwar Stone" is in it.
Japanese name refers to language = 'Japanese'; card "Fellwar Stone" refers to name = 'Fellwar Stone'
SELECT T2.translation FROM cards AS T1 INNER JOIN set_translations AS T2 ON T2.setCode = T1.setCode WHERE T1.name = 'Fellwar Stone' AND T2.language = 'Japanese' AND T2.translation IS NOT NULL