The charity is keen to ensure that teenagers are aware they can contact ChildLine online. Hot Cherry will encourage teenagers to open up and to make contact with the help-line - either by telephone or online.
The campaign is backed by celebrities including Marvin Humes of boy band JLS and actor Nicholas Hoult, a star in Channel 4's teenage drama series Skins. It will also be supported with posters in schools, online advertising and a TV campaign.
It will try to create buzz in influential online communities including celebrity, teen, music, film and gaming.
'The "how u feelin?" initiative marks a milestone in the way the NSPCC has embraced social media to encourage young people to express themselves and make contact with ChildLine via phone or online,' said the NSPCC's senior digital account manager Emily Knee.
'Young people spend a lot of their time online, which makes this type of strategy all the more relevant,' she added.
The 'how u feelin?' campaign includes Blues Busters, an online game where teenagers have to sweep the city and collect as many negative 'moodies' as possible.
According to a recent ChildLine survey, the number of children saying they felt stressed most of the time more than doubled as they reached their teens, from 12 per cent of 11- to 13-year-olds, to 27 per cent of 14- to 16-year-olds.