Isn't it "Super lovers"?
You can check out some from Yamato Nase or CJ Michalski, most 'uke' are drawn quite childlike.
age gap
Boku No Pico LOL
http://www.mangago.me/read-manga/yamada_to_shounen/
http://www.mangago.me/read-manga/don_t_touch_daddy/
http://www.mangago.me/read-manga/kitsune_no_tama_yobai/
http://www.mangago.me/read-manga/akuma_de_keiyaku/ 2nd story
http://www.mangago.me/read-manga/hidoi_otoko_minase_masara/
http://www.mangago.me/read-manga/free_punch/
http://www.mangago.me/read-manga/oucho_haru_no_yaoi_no_romance/
http://www.mangago.me/read-manga/hisho_ikuseichuu_dj_sweet_private_secretary/ and series
http://www.mangago.me/read-manga/ai_no_kotoba_wo_uragaeshi/
http://www.mangago.me/read-manga/17_sai_no_hisoka_na_yokujou/
http://www.mangago.me/read-manga/hanaya_no_nikai_de/
http://www.mangago.me/read-manga/itou_san_kuraka_sui/
http://www.mangago.me/read-manga/mitsubana/
http://www.mangago.me/read-manga/kuroneko_wa_shippo_de_amaeru/
http://www.mangago.me/read-manga/kimi_to_parade/ and sequel(?)
http://www.mangago.me/read-manga/end_game/
http://www.mangago.me/read-manga/korotto_ochita/
http://www.mangago.me/read-manga/sweet_life/
http://www.mangago.me/read-manga/boku_no_mama_chan_43_kaihatsu_nikki/
http://www.mangago.me/read-manga/dou_imo_nara_nai/
http://www.mangago.me/read-manga/amefurashi_shunu_ni_shippori_to_nureru_ooedo_renaitan/
Not a shots but Otokoro has quite the age gap and Jun is super cute
Try on Myreadingmanga!
My shota list: http://www.mangago.me/home/mangalist/118719/
I'm sorry if you didn't like this post. But can someone Tell me a Yaoi :
1. Age gap, that more than 5 Years. ;and
2. Cute ang Fluffy Shotacoon
Thank You...