Here are the Top 10 Light Novels in Japan for the week of December 10-16, 2018.
Sorry this one is a bit late. The holidays have really done a number on my schedule.

10. *6,673 **6,673 Gekijouban Dragon Ball Super: Brolly
aka 劇場版 ドラゴンボール超: ブロリー
aka Dragon Ball Super: Broly
The manga is licensed for English release by Viz
The Dragon Ball Super anime is currently streaming on Crunchyroll
The novel adaptation of the twentieth movie in the Dragon Ball series, and the first to carry the Dragon Ball Super branding

*9. *7,052 132,884 Yahari Ore no Seishun Love Comedy wa Machigatteiru. Vol.13
aka やはり俺の青春ラブコメはまちがっている。
aka My Youth Romantic Comedy is Wrong as a I Expected
https://www.novelupdates.com/series/yahari-ore-no-seishun-love-come-wa-machigatte-iru/
26 episode anime covered volumes 1-11
Licensed for English release by Yen On. Volume 7 will release February 19, 2019

*8. *7,233 *13,193 Honzuki no Gekokujou: Shisho ni Naru Tame ni wa Shudan wo Erandeiraremasen Part 4 Vol.5
aka 本好きの下剋上 ～司書になるためには手段を選んでいられません～
aka Ascendance of a Bookworm
https://www.novelupdates.com/series/ascendance-of-a-bookworm/
No English license for the light novels. The manga is being released in English by J-Novel Club

*7. *7,852 *19,567 Hataraku Maou-sama! Vol.20
aka はたらく魔王さま!
aka The Devil is a Part-Timer!
http://www.b2c.hachettebookgroup.com/series/the-devil-is-a-part-timer/?yen
Licensed for English release by Yen On. They just released volume 12.
13 episode anime aired April-June 2013 & covered volumes 1-2

*6. 10,475 *12,756 Itai no wa Iya nano de Bougyoryoku ni Kyokufuri Shitai to Omoimasu. Vol.5
aka 痛いのは嫌なので防御力に極振りしたいと思います。
aka I hate being in pain, so I think I’ll make a full defense build., I Hate Getting Hurt, So I Put All My Skill Points Into Defense
https://www.novelupdates.com/series/itai-no-wa-iya-nanode-bogyo-ryoku-ni-kyokufuri-shitai-to-omoimasu/
No English license has been announced for the light novels
An anime adaptation has been recently announced as being in production.

*5. 12,124 *12,124 Tantei Team KZ Jiken Note: Kieta Kuroneko wa Shitteiru
aka 探偵チームKZ事件ノート 消えた黒猫は知っている
aka Detective Team KZ’s Case Notes
Had a 16 episode anime that aired October 2015 – January 2016. Can be streamed on Crunchyroll.
There is no English license for the series.

*4. 12,982 *12,982 Goblin Slayer Vol.9
aka ゴブリンスレイヤー
https://www.novelupdates.com/series/goblin-slayer/
Licensed for English release by Yen On. Volume 6 releases January 22, 2019
12 episode anime streaming on Crunchyroll. Covered volume 1-2 with a short story from volume 4.

*3. 16,137 *39,458 Sword Art Online Alternative: Gun Gale Online Vol.9
aka ソードアート・オンライン オルタナティブ ガンゲイル・オンライン
https://www.novelupdates.com/series/sword-art-online-alternative-gun-gale-online/
Licensed for English release by Yen On. Volume 3 releases in February 2019.
The series is written by Keiichi Sigsawa who is the author of Kino’s Journey.
12 episode anime streamed on Crunchyroll. Covered volume 1-3

*2. 51,711 *51,711 Dungeon ni Deai wo Motomeru no wa Machigatteiru Darou ka Vol.14
aka ダンジョンに出会いを求めるのは間違っているだろうか
aka Is It Wrong to Try to Pick-Up Girls in a Dungeon
https://www.novelupdates.com/series/dungeon-ni-deai-o-motomeru-no-wa-machigatte-iru-darou-ka/
Licensed for English release by Yen On. 12 volumes released. Volume 13 comes out March 2019
13 episode Anime series streamed on Crunchyroll and covered the 1st 5 volumes.

*1. 66,007 142,672 Sword Art Online Vol.21
aka ソードアート・オンライン
https://www.novelupdates.com/series/sword-art-online/
Licensed for English release by Yen On. Volume 15 releases December 18, 2018
New season of the anime is currently airing, covering the Alicization Arc.
First new volume since September 2017
First new material not covered in the webnovel – First original material since 2008

Here are the Top 10 Light Novels in Japan for the week of December 3-9, 2018.
Big changes on the list this week. Only 1 light novel series managed to remain on the list from last week.
And yeah, the predictable title is on top. But, wow, look at the sales!

10. *6,243 **6,243 Isekai Izakaya “Nobu” Vol.5
aka 異世界居酒屋「のぶ」
aka Different World Tavern Nobu
https://www.novelupdates.com/series/isekai-izakaya-nobu/
No English license for the light novels. Udon Entertainment has announced a license for the spin-off manga
had a 24 episode anime series which aired April-September 2018 (episodes were about half length)

*9. *6,568 **6,568 Heavy Object Vol.16
aka ヘヴィーオブジェクト
https://www.novelupdates.com/series/heavy-object/
No English license for the light novels or manga.
The 24 episode anime is licensed in NA by Funimation. The anime covered Volume 3, Chapter 3 & Epilogue

*8. 10,506 *10,506 Kyoukaisenjou no Horizon Vol.29 (Vol.11 Part C)
aka 境界線上のホライゾン
aka Horizon in the Middle of Nowhere
https://www.novelupdates.com/series/kyoukai-senjou-no-horizon/
No English License
Had two 13 episode anime seasons, which aired in 2011 & 2012

*7. 11,187 *13,051 Bleach: Can’t Fear Your Own World Vol.3
https://myanimelist.net/manga/106602/
No English license for this light novel series.
The manga is released by Viz. The final volume, 74, released October 2, 2018
A 366 episode Anime based on the manga is available on Crunchyroll

*6. 11,472 125,832 Yahari Ore no Seishun Love Comedy wa Machigatteiru. Vol.13
aka やはり俺の青春ラブコメはまちがっている。
aka My Youth Romantic Comedy is Wrong as a I Expected
https://www.novelupdates.com/series/yahari-ore-no-seishun-love-come-wa-machigatte-iru/
26 episode anime covered volumes 1-11
Licensed for English release by Yen On. Volume 7 will release February 19, 2019

*5. 11,715 *11,715 Hataraku Maou-sama! Vol.20
aka はたらく魔王さま!
aka The Devil is a Part-Timer!
http://www.b2c.hachettebookgroup.com/series/the-devil-is-a-part-timer/?yen
Licensed for English release by Yen On. They just released volume 12.
13 episode anime aired April-June 2013 & covered volumes 1-2

*4. 13,184 *13,184 IDOLiSH7: Re:member
Started as a video game in Japan. Has since spawned albums, anime, manga, and light novels.
This Light Novel appears to adapt the manga series by the same name, which focused on the background of the idol group Re:Vale

*3. 21,156 *23,806 Haikyuu!! Shousetsu-ban!! Vol.10
is a light novel adaption of Haikyū!!, written by Kiyoko Hoshi
The manga is published in English by Viz
60 episode anime is licensed in NA by Sentai Filmworks

*2. 23,321 *23,321 Sword Art Online Alternative: Gun Gale Online Vol.9
aka ソードアート・オンライン オルタナティブ ガンゲイル・オンライン
https://www.novelupdates.com/series/sword-art-online-alternative-gun-gale-online/
Licensed for English release by Yen On. Volume 3 releases in February 2019.
The series is written by Keiichi Sigsawa who is the author of Kino’s Journey.
12 episode anime streamed on Crunchyroll. Covered volume 1-3

*1. 76,665 *76,665 Sword Art Online Vol.21
aka ソードアート・オンライン
https://www.novelupdates.com/series/sword-art-online/
Licensed for English release by Yen On. Volume 15 releases December 18, 2018
New season of the anime is currently airing, covering the Alicization Arc.
First new volume since September 2017
First new material not covered in the webnovel – First original material since 2008

Here are the Top 10 Light Novels in Japan for the week of November 26 to December 2, 2018.

10. *5,479 **5,479 Youseiryuu wo Kainarase Vol.6

*9. *5,515 **5,515 Hisshou Dungeon Unei Houhou Vol.10
aka 必勝ダンジョン運営方法
aka The Way to Absolute Dungeon Administration – There Is No Reason To Meet With the Opponent!
https://www.novelupdates.com/series/hisshou-dungeon-unei-houhou/
No English License for the light novels.

*8. *5,690 *25,050 Rokudenashi Majutsu Koushi to Akashic Records Vol.13
aka ロクでなし魔術講師と禁忌教典
aka Akashic Records of the Bastard Magical Instructor
https://www.novelupdates.com/series/akashic-records-of-the-bastard-magical-instructor/
No English license for the light novels.
The manga is licensed for English release by Seven Seas. Volume 5 released in November 2018.
Anime adaptation – 12 episodes covering the first 5 volumes. Licensed in NA by Funimation.

*7. *6,529 **6,529 Kenja no Deshi wo Nanoru Kenja Vol.10
aka 賢者の弟子を名乗る賢者
aka She Professed Herself The Pupil Of The Wiseman
https://www.novelupdates.com/series/she-professed-herself-the-pupil-of-the-wiseman-ln/
No English license for the light novels.

*6. *6,860 **6,860 Deokure Tamer no Sono Higurashi Vol.2
Same author as I Was a Sword When I Reincarnated

*5. *7,019 **7,019 Last Embryo Vol.6
aka ラストエンブリオ
https://www.novelupdates.com/series/last-embryo/
No English License for this title or it’s prequel.
Sequel series to Problem Children Seem to be Coming from Another World? which had a 10 episode anime adaptation.

*4. *7,850 **7,850 Seirei Gensouki Vol.12
aka 精霊幻想記
aka Seirei Gensouki Spirit Chronicles
https://www.novelupdates.com/series/seirei-gensou-ki/
Licensed for English release by J-Novel Club. Volume 3 releases in English February 4, 2019

*3. *8,245 109,399 Mahouka Koukou no Rettousei Vol.27
aka 魔法科高校の劣等生
aka The Irregular at Magic High School
https://www.novelupdates.com/series/mahouka-koukou-no-rettousei/
Licensed by Yen On. Volume 10 is being released December 18, 2018
26 episode Anime covered volume 1-7 excluding volume 5. Available on Crunchyroll

*2. *8,250 *13,715 Kidou Senshi Gundam NT
https://www.novelupdates.com/series/kidou-senshi-gundam-uc/
No English license for the Light Novel
Novel adaptation of the film of the same name. Which itself is based on the 11th volume of the Gundam Unicorn novel series.

*1. 21,956 114,360 Yahari Ore no Seishun Love Comedy wa Machigatteiru. Vol.13
aka やはり俺の青春ラブコメはまちがっている。
aka My Youth Romantic Comedy is Wrong as a I Expected
https://www.novelupdates.com/series/yahari-ore-no-seishun-love-come-wa-machigatte-iru/
26 episode anime covered volumes 1-11
Licensed for English release by Yen On. Volume 7 will release February 19, 2019