Visiting Relative Visa for Japan from India

So I work in Japan (5 year work visa) and I want to invite my mother to Japan for 30 days. Earlier in this year, I invited my friend on visiting friends visa so I am familiar and confident with the process.
The last name in mother's name on my passport is different than the last name in her passport, though the proof of relationship will be birth certificate which has the exact name as her passport, I wanted to know if anyone has gone through similar problem and what happened ? Whether I should take risk or not, or any additional documents I can submit to prove they are the same people.
My second option is to apply for tourist visa (with refundable hotel bookings) for her, in that case my father will be sponsoring her trip so the sponsorship letter is to be included in the cover letter and consent letter from spouse or to be submitted separately ? Does anyone has experience applying for visa to travel solo to japan with sponsorship from parents/spouse ?