Many of Lewis' recent Under 18 graduates have gone on to represent Wales Under 20, Wales Sevens and Wales with Hallam Amos and Dafydd Howells, both capped last year having travelled to South Africa with the side just two years ago.
There was success over southern hemisphere opposition in the autumn with wins over Australian Schools A and Australian Schools, and the squad preparing to play France tomorrow and England next week is a mix of those players and new players to the squad.
Lewis said: "Our work is to try to close the gap, both between age groups, and between our nation and the top few sides in the world game. We were pleased with our wins over Australian Schools in December, which shows that you can also win games when prioritising a ball-in-hand game. We beat France twice last year and when we had the players together as a squad, we came within the final kick of beating England.
"We want players to almost 'over play' at Under 16 and Under 18 level and we are focussing on the performance rather than the result in order to develop players for the future. We are a small nation and that means we sometimes need to work on developing individuals rather than concentrate on a team at a young age in order to maximise the talent we have available to us and ensure those players are ready for the very highest level.
Wales Under 18 squad to play France today (Chartres) and England next Sunday 23 March at the Gnoll (1.45pm):
Kieron Assirratti (Blues/ Coleg y Cymoedd/ Wattstown), Keagan Bale (Dragons/ Coleg Gwent / Caerleon), Robert Lewis (Blues/ St Peters / Coleg y Cymoedd), Leon Brown (Dragons/ Newport High), Harrison Walsh (Ospreys / Bishopgore / Mumbles), Liam Belcher (Blues/ Coleg y Cymoedd / Pontypridd), Dafydd Hughes (Scarlets / Llandovery College / Llandovery), Matthew Dodd (Ospreys / Olchfa / Dunvant), Seb Davies (Blues / Coleg y Cymoedd / Pentyrch), Calum Haggett (Blues / Coleg y Cymoedd / Gilfach Goch), Josh Middleton (Scarlets / Coleg Sir Gar / Kidwelly), Tom Phillips (Scarlets / Coleg Sir Gar / Llangennech), Jon Fox (Ospreys/ Gower College / Swansea), Harrison Keddie (Dragons / Coleg Gwent / Caerleon), Josh Cole (Ospreys / Neath Port Talbot College / Tonmawr)
Backs: Michael Hale (Blues / Glantaf / St Josephs), Owen Davies (Dragons / Monmouth Boys School / Oakdale), Kieran Hardy (Scarlets / Coleg Sir Gar / Pontyberem), Thomas Williams (RGC/ Rydal Penrhos / Newtown), Dan Jones (Scarlets / Coleg Sir Gar / Carmarthen Quins), Owen Watkin (Ospreys / Bridgend College / Bryncethin), James Whittingham (Blues / Cowbridge), Morgan Williams (RGC/ Coleg Llandrillo / Caernarfon), Rhys Gealy (Ospreys / YG Gwyr / Pontarddulais), Lloyd Lewis (Dragons / Ysgol Gwynllyw), Shaun Pearce (Scarlets / Glan y Mor / Bury Port)