In the 2013 movie 'Her', Joaquim Phoenix's character Theodore falls in love with his operating system, but fiction may be turning into reality after a man in Japan reportedly 'married' a hologram of his virtual home assistant. 

Akihiko Kondo reportedly splashed out two million yen - around $17,500 - on a ceremony to wed 'Hatsune Miku' at a Tokyo hall, although the union is not legally recognised in Japan. 

The Miku hologram is a blue-haired, 16-year-old virtual reality singer and was represented in the ceremony by a small stuffed doll. 

Although around 40 guests were in attendance, they reportedly did not include any of his family members, notably his mother. 

'For mother, it wasn't something to celebrate,' the 35-year-old told AFP news agency. 

The talking Miku hologram appears via a $2,800 desktop device and performs simple tasks like waking him up in the morning and turning the lights off.  

Kondo says he has been faithful to her.

'I never cheated on her, I've always been in love with Miku-san,' he said. 'I've been thinking about her every day.'

Kondo says his marriage is 'cross-dimension' and that he and thousands of others in relationships just like him have received a 'marriage certificate' from the manufacturer of the hologram device, Gatebox.

He believes the hologram has qualities that no real women can offer - like fidelity, immortality and eternal youth. 

'I'm not seeking these in real women. It's impossible,' he said. 'I believe we must consider all kinds of love and all kinds of happiness.'

It's the latest trend to go against traditional marriage in recent years after reports of more people choosing sologamy - the practice of marrying oneself.