tMnR http://www.pixiv.net/member.php?id=172165

Also known as Yukiiti and Yuki no Hitohira

tMnR's UmiEli works can be considered a "series" as they all have a loose connection. However, they were /not/ released in chronological order, and they do /not/ assume you have read the previous works (except for the ones explicitly titled "Part 1" "Part 2"). They are not a strict "series" in the traditional sense and there's not currently any larger banner we can describe them under.

>>>If you're interested, the chronological order is as follows:<<<

Deep Blue Sea Like Me → The Secret Shokolad (vol. 1) → The Secret Shokolad (vol. 2) → Fortunate Re”lation [ re-release of Fortunate Relation; not yet scanlated] → Your Straightforward Expression → Passion → Time for sweet living /As Our Lives Become Interwoven/Another work that waiting for release (not 100% sure on the chronological order of last two)
(via Shimapanda from Girls in Boxes)

Rely On Me More! Love Live! Doujin released Oct 21 '14 Eli x Umi Yuri
Happy Birthday Eri! Love Live! Doujin released Nov 14 '14 Eli x Umi Yuri
Deep Sea Blue Like Me Love Live! Doujin released Dec 24 '14 Blushing Eli x Umi School life Yuri
Your Straightforward Expression Love Live! Doujin released Sep 5 '15 Eli x Umi Yuri
Passion Love Live! Doujin released Sep 5 '15 Beach Eli x Umi Romance Swimsuits Yuri
Fortunate Relation by nwonyo pasun and tMnR Love Live! Doujin released Oct 21 '15 Eli x Umi Romance Yuri
Happy Birthday Umi Sonoda Love Live! Doujin released Mar 25 '16 Eli x Umi Yuri
Time for sweet living Love Live! Doujin released Oct 10 '16 Bath Blushing Eli x Umi NSFW Romance Yuri
As Our Lives Become Interwoven Love Live! Doujin released Mar 15 '17 Eli x Umi Sequel Yuri