Magento – Importing customer with names in Japanese – Required attribute ‘firstname’ has an empty value for all rows

I am trying to Import customers with their names in Japanese(katakana). It shows following error in validation results (On linux machine)

Required attribute 'firstname' has an empty value in rows: 1,2,3,and so on

The values are there in the column for firstname, but still it says empty value. If I enter English characters instead of Japanese, it accepts and does not show any error.

If I do the same thing on Windows OS, same file with Japanese characters works perfectly.

Not sure, if its a Magento's bug or I need to do something differently?

If anyone has a solution or any suggestion, please let me know

File format is .csv, Encoding utf-8

The contents of the file are:

email,_website,_store,firstname,lastname,password_hash,created_in,store_id,group_id,website_id,prefix,middlename,suffix,dob,taxvat,confirmation,gender,created_at,rp_token,rp_token_created_at,disable_auto_group_change,password,_address_firstname,_address_lastname,_address_country_id,_address_region,_address_postcode,_address_city,_address_street,_address_telephone,_address_fax,_address_company,_address_prefix,_address_middlename,_address_suffix,_address_vat_id,_address_default_billing_,_address_default_shipping_
john.doe@example.com,base,default,金魚,金魚,2049484a4020ed15d0e4238db22977d5:eg,,1,1,1,,,,,,,,"2007-08-31 00:23:13",,,0,,,,,,,,,,,,,,,,,